- “Please Sir, call me... Mandark!”
- ―Mandark in Dexter's Rival
Mandark (real named as Susan Astronomanov) is the overall main antagonist in Dexter's Laboratory. He is Dexter's rival and later arch-nemesis who often seeks to destroy both Dexter and his lab to prove once and for all that he is the superior genius. He is voiced by Eddie Deezen.
Mandark is an evil boy genius who is bent on the destruction of Dexter's Laboratory and ruling the world. He is an incredibly intelligent individual who, when first introduced, was leagues ahead of Dexter in terms of knowledge and accomplishments, but after having his lab and heart destroyed by Dexter and Dee Dee, his scientific skills became far less impressive than Dexter's, likely due to the mental trauma of seeing his greatest works completely destroyed and having his first love be used against him. Ever since, Mandark has always been one step behind Dexter and has done all he can to get the better of his rival and prove once and for all that he is the superior boy genius, but every time he tries to, he always ends up failing horribly. After Mandark's laboratory was destroyed, he eventually built a new one to resemble the old, but eventually he remodeled his lab and gave it a darker and more gothic-look, with many of the machines being replaced with bio-mechanical equipment; apparently meant to represent Mandark's growing evil nature, which was a result of his ever growing hatred for Dexter and his constant failures. His dark desires and evil ego continued to grow throughout his life, and by the time he reached adulthood, he became a full-blown supervillain who desired the complete take over and enslavement of the planet. It is implied that Mandark's dark nature is due to living a lonely life, as mentioned in "Mandarker", where he states that he has no friends or hobbies and the only thing he had in life was his lab and experiments. Eventually though, Mandark would gain an interest in surfing after "Sun, Surf, and Science" and gained his first real friend in the form of the Surfer Boy. In seasons 3 and 4, Mandark's motives and personality were drastically changed, with the story implying that he had always been evil even since his birth and always had the gothic motif he had in said seasons.
However, there is another side to Mandark's personality, which is his intense love for Dee Dee. Ever since he first laid eyes on her, Mandark has been completely enamored with her to the point of obsession and whenever he is not focusing on his evil plans or hatred towards Dexter, he only thinks of his beloved Dee Dee and dreams of what kind of relationship they would have. Despite this, Dee Dee has shown no interest in Mandark and at times seems to outright hate him or look down on him, and barely ever shows any non-hostile feelings towards him, but regardless, Mandark's love for her remained unchanged throughout the series and he continued to love her unconditionally. In fact, even when Mandark was completely corrupted and became the evil and heartless Overlord Mandark in the future, the one thing that remained unchanged about him was his eternal love for Dee Dee which is without a doubt a permanent trait of his personality that would stay with him even in his later years. It was this love that would eventually lead to his own defeat in the future. Regardless, Mandark continues to love Dee Dee above all else; caring more about her well-being than even Dexter at times, with Mandark continuing to love her even when she destroyed his future empire while Dexter instead wanted her destroyed for taking the glory from him.
Mandark is a tall boy who has a black bowl-cut hairstyle that lays around the top of his head like a helmet. It has a white shiny glare on it and an M shaped opening at the bottom. This hairstyle was passed down to him by his father Windbear which was also passed down to his little sister Lalavava. Mandark has a head that is big at the top and gets skinnier at the bottom near his neck. He has nerdy glasses which look exactly like Dexter's and he wears a white dress shirt, a yellow tie with black stripes, blue shorts, and brown shoes.
As Susan Astronomanov
Mandark lives in the peaceful land of Flowertopia where his hippie parents Oceanbird and Windbear were in a lake giving birth to him. With Oceanbird's last breath of maternal exhalation, she had finally brought her new born lovechild into the world. They both wanted their son to be good and just like them, as soon as he was born, he was struck by a random bolt of lightning which made him truly evil on the inside.
Later, Oceanbird and Windbear were up on top of a hill where they thought about what they would name him. Oceanbird and Windbear named their child Susan because Oceanbird had requested a name without the preconcieved gender connitations. The moment the two of them named him Susan, he started crying. Oceanbird and Windbear started teaching him all about their hippie beliefs and made him do it with them. Their full intent was for him to be a good and pure flowerchild and for him to believe in peace just like them. Susan however, was still truly evil on the inside and didn't like this. Just then, Susan came across a metal gizmo on the ground. He loved everything about it and was mezmorized by how gret it was. He turned it on and it was a light bulb. Susan wanted to know everything about this and to be someone who is related to science. However, his plans for said thing would have to wait, because Oceanbird and Windbear had a different idea for his development.
Oceanbird and Windbear constantly kept doing hippie rituals with him. Activity after activity and he didn't like any of them and alsways tried to be evil. They tried making him hug trees, but he ate the trees. They tried painting beautiful murials, but he painted demonic horrors, and they tried balancing amethysts, which Mandark hated. Years after, on Susan's 8th birthday (which they ironically address to as his annual name day), Susan finally snapped because he couldn't take any more of this. He said he was done with this. He wanted meat, and he wanted science. Oceanbird and Windbear came to the realization that they were neglecting their son's needs and then had the idea to drop out. They tried traveling the world to try and cure his craving for evil and technology and Susan went along with this and did not deny it. Even though he wanted to become good, he still had the need to be evil.
Oceanbird and Windbear moved out of their town and into the neighborhood where Mandark lives now. He tried to make friends with Dexter but Dexter laughed at him for being dressed like a girl, because Mandark has a large hair, a pink uniform with a flower and two pink sandals. Susan was so angry about being made fun of that he decided to become an evil genius named Mandark.
As a Dark Mandark
Mandark kidnapps Dexter's Mom and disguises himself as Dexter's Mom
As Mountain Mandark
As a Executive
Executive Mandark lives in the future where he is the oppressive and slave driving boss of The Corporation. He and Dexter were both originally hired by the company as equal research scientists to work on new ideas to better the future, however Mandark was unable to come up with new ideas so he began stealing Dexter's ideas and presented them to the heads of the company as his own. Eventually he was able to climb the corporate ladder and overthrow the company's executives, allowing him to become the head of The Corporation and he began ruling over the other employees and treating them like slaves.
He then used his new power to constantly torment Number 12 and would laser whip him whenever he was late for work or did even the smallest error, this resulted in Mandark having completely broken Dexter's mind and confidence and turning him into his own bumbling slave. Eventually, the young Dexter from the present appeared and restored Number 12's confidence and took him to the far future to meet Old Man Dexter, but in the past, Number 12 had accidentally left his Neurotomic Protocore exposed, allowing Executive Mandark to swipe it and use it for his long awaited evil goals.
When the time traveling Dexters prepared to battle Executive Mandark's future and neurotomically empowered self, Overlord Mandark, he summoned his own past selves to help him, including Mandark, Executive Mandark and Braindark. During the fight, Executive Mandark easily overwhelmed Number 12 by slapping him across the face and reminding him of his superiority. However when Executive Mandark broke his glasses, he had broken Number 12's last straw, thus unleashing a bestial rage within Number 12 and turning him into the true Dexter he once was and instantly punched out the fearful Executive Mandark. When the Dexters prepared to deactivate the Neurotomic Protocore, each of them were grabbed by their respective Mandark, but before they could deactivate it, Dee Dee appeared from Dexter's Time Machine and all the Mandark's immediately fell in love after seeing their beloved Dee Dee after so long. Dee Dee then unknowingly de-activated the Protocore and set its energy output to positive, which undid all of Overlord Mandark's evil and Mandark, Executive Mandark and Braindark where then sent back to their own time periods.
As a Overlord
In his past, Overlord Mandark was Executive Mandark, the head of The Corporation who treated his employees like slaves and loved to torment his most hated former adversary Number 12 aka Dexter's adult self. One day, the Dexter from the past appeared to restore Number 12's confidence and took him to the future to meet Old Man Dexter to find out how they saved the future. However, Number 12 had accidentally left his Neurotomic Protocore exposed, allowing Executive Mandark to finally steal his most long sought after goal from Dexter. He then tried to harness the power of the Protocore but set its positive flow to negative. The now corrupted energies of the core began to twist Mandark's already crooked mind, making him more greedy and insane than ever before. The negative energies emitted by the Protocore numbed the minds of the planet's populace, allowing him to easily take control of all the world's technology, knowledge and societies, thus becoming the absolute evil ruler of the world. With his new found power and luxuries, Mandark spent the majority of his time lounging in hot tubs and became quite obese over time and needed a grappling hook just to move about. Most of his actions involved trying to thwart Action Dexter's attempts to help the populace.
When the time traveling Dexters prepared to battle Overlord Mandark, he immediately sent his robots to destroy them but when that failed and they arrived at his fortress, Overlord Mandark summoned his own past selves to help him, including Mandark, Executive Mandark and Braindark. During the fight, Overlord Mandark and Action Dexter had an epic clash and exchanged numerous and painful heavy blows. Eventually Action Dexter was able to gain the upper hand by loosening Overlord Mandark's grappling hook, causing him to fall flat on his face. When the Dexters prepared to deactivate the Neurotomic Protocore, each of them were grabbed by their respective Mandark (the Overlord doing so with the aid of his bulldozer), but before they could deactivate it, Dee Dee appeared from Dexter's Time Machine and all the Mandark's immediately fell in love after seeing their beloved Dee Dee after so long. Dee Dee then unknowingly de-activated the Protocore and set its energy output to positive, which undid all of Overlord Mandark's evil and caused his body to explode, leaving behind only his brain and thus turning him into Braindark. Mandark, Executive Mandark and Future Braindark where then sent back to their own time periods. Braindark's disembodied brain was then placed in a confined jar with a communicator by Action Dexter where he would spend the rest of his days as punishment for his evil crimes.
As a Braindark
Braindark lives in the far future of Dextopia where Old Man Dexter permanently imprisoned him in a brain jar for his crimes against the world and is forced to reside in the Dexter Museum. His jar is completely immobile so there is not much he can do other than talk and yell out insults like a grumpy old man. When the time traveling Dexters prepared to battle Overlord Mandark, he summoned his own past selves to help him, including Mandark, Executive Mandark and Braindark. During the fight, Braindark and Old Man Dexter simply exchanged senile insults. However Braindark's insults appeared to be weakening Old Man Dexter's resolve, but eventually Old Man Dexter was able to gain the upper hand and escape the barrage of insults. When the Dexters prepared to deactivate the Neurotomic Protocore, each of them were grabbed by their respective Mandark, but before they could deactivate it, Dee Dee appeared from Dexter's Time Machine and all the Mandark's immediately fell in love after seeing their beloved Dee Dee after so long. Dee Dee then unknowingly de-activated the Protocore and set its energy output to positive, which undid all of Overlord Mandark's evil and caused his body to explode, leaving behind only his brain and thus turning him into Braindark. Mandark, Executive Mandark and Future Braindark where then sent back to their own time periods.
The following events are only referenced in seasons 3 and 4, and posses inconsistencies that contradict events and characters from seasons 1 and 2. Along with the fact that following events are not the work of series creator Genndy Tartakovsky, their canonicity is uncertain and possibly apocryphal.
Birth and Early Childhood
Mandark was born the son of the hippie pacifists known as Windbear and Oceanbird in the annoyingly peace loving hippie community of Flowertopia and was birthed by his mother while in a small wooden pool of water. Upon being born, Mandark was already tainted with a dark and evil disposition, almost as though a dark presence had zapped him with unspeakable evil, however his parents were completely unaware of this.
As his parents thought up a name for their child, they expressed that they wanted a name that was beyond the conforms of society, beyond the preconceived gender connotations, a name that is whispered softly through the canyon winds, and so they named him Susan, which immediately made the infant Mandark cry with grief.
One day, an infant Susan was wallowing about his shameful habitat of life when he came across a strangely placed piece of technology that had found its way into the middle of Flowertopia with no explanation as to why. Susan loved everything about this device, he loved the way it looked, the way it felt, the way it worked. When he turned it on, it created a bright light that inspired Susan to learn more about technology and science. He knew that if he could only master this thing called science he would be able to control the world. Oceanbird and Windbear however did not approve of this. They believed in living on earth the way it was created, back when it was pure and not overrun by technology, and so they took it from and him and instead did many activities together with him such as loving nature and meditation, but none of this pleased Susan as he hated all of it because they all had nothing to do with technology, science or evil.
When a young Susan let out his frustration and rejected his hippie lifestyle on his birthday, his parents decided to venture out into the world in hopes of potentially helping Susan find what he was looking for. As they traveled the world, Susan still felt discontent with his life and lack of technology, no matter how beautiful the places they went to were.Eventually, the trio decided to settle down and moved into a suburban neighborhood in a nice and small house. During this time, Susan was already an older child and while he was out for a walk one day, he came across his future rival Dexter who was building an invention of his out on his sidewalk. When Susan saw this, he was fascinated by how outstanding it was. He knew this was science and he wanted to know all about it. He greeted Dexter and wanted to be friends with him, however Dexter rejected his requests as he was far too busy and said goodbye while calling him a little girl. Susan tried to tell him that he was actually a boy, but because he looked so much like a girl with his long hair and pink dress, Dexter was confused as to how he could be a boy. He then asked what his name was and with reluctance, Susan revealed his name. Dexter then burst out into laughter over this hilarious revelation. Susan was so annoyed and angered by his laughter and mockery that he became enraged and decided that he would no longer embrace his peaceful hippie facade and swore vengeance on Dexter. He ran up into his room, and took his childhood device and started to build himself an evil laboratory where he would be able to create his own evil experiments with technology which would help him take over the world. He then changed his physical appearance to become more fitting of his gender. He gave himself a bowl-cut hairdo where he literally took a bowl and cut his hair along the rim of it, and he then donned on a proper suit and tie. To complete his change, he began to think of a new name for himself, one that would express the darkness that flowed through him, and the man that he knew he was destined to be. Susan then became Mandark and found his one true goal in life, to dominate Dexter, the world, and become the greatest genius ever.
Inconsistencies end here.
In seasons 1 and 2, it is known that Mandark was born to parents of presumably Russian descent who bore the family name Astronomanov before the characters were developed into Oceanbird and Windbear, who lacked last names. His parents later gave birth to his younger and overbearing sister Olga Astronomanov aka Lalavava. Depending on what events from seasons 3 and 4 fit in with the continuity of seasons 1 and 2, not much is known about Mandark's past.
Mandark was apparently a lonely child who had no friends and had no talent with sports. The only thing Mandark excelled at was his scientific and technological skills. Later on, Mandark created his highly advanced and gigantic laboratory in his backyard and since he lacked friends or sports skills, his lab became his whole life and his sole reason for being. At an unknown point, Mandark, in his pursuit of advancing his research and knowledge, discovered the very secrets of magic and dark arts after having somehow come in contact with an inter-dimensional being known as JoJo who helped him to understand and even write a book on the subject titled "The Magic of Science", and Mandark then formed a sinister pact with Dark Forces, which likely began his eventual corruption over time.
When Mandark started going to Huber Elementary School on the first day of the school year, he would end up meeting his future rival Dexter and as soon as they came face to face, Mandark proved that he was the far superior intellect. Upon their first meeting, Mandark proved that he was far smarter than Dexter and even won over the affections of Dexter's beloved teachers. To try and prove that he was still superior, Dexter showed Mandark his laboratory thinking it would mean that he was smarter than him, but then Mandark revealed that he had an even bigger and better laboratory. Mandark then forced Dexter to shut down his lab, or else become Mandark's lackey, and Dexter, unable to let go of his pride, shut down his laboratory.Dexter thought that it was all over for him until one day while Mandark was wooing the teachers, he heard the voice that would captivate his heart for all eternity, the voice of Dexter's sister Dee Dee. Upon first setting his eyes on her, Mandark fell completely in love with this "golden haired angel" and desperately went to Dexter to find out who she was only to learn that she was Dexter's sister, which made Mandark beg for Dexter to set her up on a date with him. Realizing he could take advantage of this, Dexter told Mandark how to "invite" Dee Dee over to his house by luring her with candy and entertaining her with "dancing", knowing full well that Dee Dee would go on a destructive ballet rampage if she was asked to dance. When she arrived to Mandark's laboratory, Mandark quickly offered his beloved to dance and invited her upstairs where he proceeded to ask her to dance with him, and as Dexter had anticipated, Dee Dee went on a dancing rampage and destroyed Mandark's laboratory much to Mandark's shock and horror. Dexter watched all this occur from his spy cams and he happily made a toast to his beloved and reactivated Computer who was happy to be back. After this event, Dexter had officially become the superior boy genius and Mandark became his eternally one-step-behind rival much to Mandark's disbelief. From this day forth Mandark swore to have his revenge on Dexter and do whatever it takes to defeat him and destroy his lab.
Return of MandarkA short time after their first encounter, Mandark was still solemn and bitter after having both his lab and his heart destroyed by his one true love and was even suffering from recurring nightmares due to the trauma, which made him lay awake at night while swearing vengeance upon Dexter for what he had done to him. The next day at school, Mandark watched on as the class praised Dexter's genius as he gloated about his superiority and his goal to win the science fair. An angry Mandark sitting in the back of the class was unable to hold back his frustration and called out everyone for their mindless fanaticism towards Dexter and even told Mr. Luzinsky to hold his tongue, as he believed that Dexter was unworthy of any praise, especially after what he had done to him, solemnly telling them of how Dexter used his own love for Dee Dee against him and completely destroyed his lab, leaving him with absolutely nothing when in contrast all he had made Dexter do was shut down his lab rather than destroy it nor messed with his emotions. He then revealed that he planned to take part in the town science fair as well where he would defeat Dexter, however Dexter remained unfazed by his threats and ignored him. The following night, Mandark tried to find anything in his destroyed lab to outdo Dexter at the science fair, but his efforts proved futile and he almost considered giving up until he found his lost copy of the The Magic of Science, knowing that its dark knowledge would allow him to completely overshadow Dexter and have his revenge. The next day during the fair, Dexter was about to win with his robotic arm until Mandark arrived dressed as a sorcerer and carrying a mysterious golden box. Mandark's late entry was accepted into the fair and he then used the arcane magic at his disposal to summon his inter-dimensional monster JoJo which then kidnapped Dee Dee, forcing Mandark and Dexter to put aside their differences and join forces to save her. After doing so, Dee Dee rewarded Dexter with a peck on the cheek and an amorous Mandark with a disturbed look and the two boys appeared to have settled their differences, at least until the two were given the blue ribbon prize. Their unwillingness to share the prize ended up re-igniting their rivalry once more.
One day at school while watching a documentary on Mount Rushmore, Dexter discussed the possibility of bringing to life the presidential sculptures (after the subject was brought up by Timothy) with the technology of Tripolar Frankensteinian Electrodes which could then be used to cause havoc and destruction, and this thorough explanation did not go unnoticed by Mandark, who grew a keen interest in Dexter's explanation, writing down everything as he spoke.The next day as Dexter is planting a cherry tree, it is suddenly cut in half by a giant stone axe wielded by the now living full bodied statue of George Washington who is being controlled by Mandark. Mandark then has George smash Dexter's home and lab, forcing Dexter to briefly retreat in order to try and bring to life his own sculpture from Mount Rushmore. Meanwhile Mandark, assuming himself to be victorious, proceeds to lounge in Dexter's pool with Washington when they are suddenly confronted by Dexter and his now animate statue of Abraham Lincoln. The boys and their statues then engage each other in an epic battle. Eventually the two statues prove to be evenly matched, and it appears the presidential statues somehow gained self-awareness, now commenting on their equal might and complimenting each other. The two eventually end the battle and leave behind Mandark and Dexter, much to their frustration, and the two statues decide to go eat some bricks.
Surfer Dude Mandark
One day while at the beach, Mandark was relaxing and researching the social and cultural aspects of the beach and its visitors until he saw his dear Dee Dee. Mandark is immediately lovestruck by her but after seeing her hanging out with a Surfer Boy, he tries to do everything he can to impress her in order make sure she does not fall in love with the Surfer Boy, however all his attempts prove futile. After apparently seeing the Surfer Boy sign up for a surfing contest, Mandark decides to enter as well in hopes of beating him and winning Dee Dee's love.
Mandark then tries his hand at surfing but proves to be terrible at it. Just when he is about to give up, he suddenly appears before a mighty Tiki God who gives Mandark's the encouragement he needs and reminds him that he must rely on his own talents. Now knowing what to do, Mandark goes to his (now rebuilt) laboratory and begins honing his surfing skills using his Indoor Wave Pool and builds a surfboard called Tiki Brand that is modified to fit his tactics. He also rigs the surfing area with booby traps so that the other surfers (especially Surfer Boy) would lose and be out of the way for good.
The next day as the contest starts up, Mandark discovers that the Surfer Boy did not enter the contest and it was in fact Dee Dee whom the Surfer Boy had entered. Realizing that Dee Dee could become a victim of his traps, Mandark does his best to protect her, all the while having to activate and suffer from his own traps. Eventually Mandark is able to destroy all the traps and Dee Dee is able to win the contest. As an unconscious Mandark begins sinking into the sea, he is saved at the last minute by the Surfer Boy who compliments his surfing skills. Having realized that the Surfer Boy was no rival and almost ended up harming him because of it, Mandark decides to invite the Surfer Boy over to his lab so they can practice their surfing on his wave pool. The Surfer Boy happily agrees and Mandark gains his first real friend.
Race Down Volcano Mountain
Sister vs Sister
Mandark's little sister, named Olga Astronomonov, who goes by the name of "Lalavava", got into a rivalry with Dee Dee the same way Dexter did with Mandark after the two girls competed to get the solo role in their Dance School's recital. After the solo was changed into a duet, the two girls sought out the aid of their brothers so they could build a device that would allow them to beat the other. However while Dexter was asked nicely by Dee Dee, Mandark was tormented and threatened by his sister. On the night of the recital, Dee Dee used the Dexo-Transformer while Lalavava used the Mandark-Transformer and each formed a deadly and destructive dance that destroyed the dance theater. Both then agreed that their brothers were stupid and that science stinks, and the two happily became friends and went to the mall.
Rise of Badaxtra
After Dexter accidentally unleashed the unstoppable monster Badaxtra which threatened to destroy humanity, Mandark saw this as an opportunity to outdo Dexter and take down Badaxtra himself using his Monster Blasting Ampliphonic Atomic Ray Cannon. However, blinded by his overconfidence, Mandark did not realize that his weapon was actually strengthening Badaxtra and the mighty beast proceeded to eat Mandark and his cannon. Later after Dexter and his family destroyed Badaxtra with the aid of Monkey empowering the Multi-Formic Megabot, Mandark was freed from the beast's stomach, and since Monkey had used a memory erasing ray on Dexter, no one remembered who stopped the monster and Mandark assumed that it was his cannon which caused it to explode, and thus he took all the credit for Badaxtra's defeat and crowned himself the hero who saved the world.
For the next many years of his childhood, Mandark continued to try and outdo Dexter while obsessing over his beloved Dee Dee. This would all change however with the creation of Dexter's greatest and most powerful invention ever, the Neurotomic Protocore, a device so powerful that it could revolutionize the world forever. The creation of this device caused Mandark to be consumed by his own dark corruption due to realizing that with this device he could become the ruler of the world. He then became determined to steal Dexter's greatest creation and completely crush him in order to achieve his goal of total supremacy, turning their once comedic and destructive rivalry into one of pure hatred and deadly force. Despite his many attempts, Mandark was never able to obtain the core during his childhood, however at one point the young Mandark would be summoned into the future for an important confrontation.
AdulthoodMany years later, a now teenaged Mandark and Dexter had been given jobs at the powerful world-conglomerate simply known as the The Corporation where they were made research scientists tasked with creating new ideas to make the future better. Early in their work, Dexter proved to be a creative machine who constantly came up with new and brilliant ideas while Mandark remained stuck with a creative block. Realizing that he was losing to Dexter, Mandark began stealing Dexter's ideas and presented them as his own to The Corporation's executives. This allowed Mandark to rise up the corporate ladder and overthrow the company heads. With this Mandark had taken over the entire company and had become Executive Mandark. Mandark had now become the richest and most influential person on the planet and during this time the world went through major technological and social changes and people everywhere had their names taken away and were instead given ID numbers. With his new power, Mandark treated all numbers who worked directly under him like mere work slaves and forced them to obey his every whim or else he would inflict physical punishment upon them. However no other employee suffered more than Number 12, who was Executive Mandark's favorite punching bag and whom he constantly subjected to public whipping in front of all other employees while mocking him; a pastime Mandark enjoyed dearly as the pathetic Number 12 was none other than his former rival Dexter whom he had successfully reduced into a bumbling coward as pay back for all the defeats he endured at his hands. With this, Mandark had finally had his revenge on Dexter, but he still had not managed to find the long lost Neurotomic Protocore.
The World of Overlord MandarkOne day, after Executive Mandark had given a severe lashing to his former rival, Number 12's past self, the young child Dexter, had traveled through time and restored Number 12's confidence and he proceeded to take Number 12 to the future with him to meet their cool future self. Fortunately for them though, all of this remained unknown to Executive Mandark. However, Number 12 had accidentally left his Neurotomic Protocore exposed before heading to the future, allowing Executive Mandark to finally steal his most long sought after goal from Dexter. He then tried to harness the power of the Protocore but set its positive flow to negative. The now corrupted energies of the core began to twist Mandark's already crooked mind into an even more evil form, making him more greedy and insane than ever before. The negative energies emitted by the Protocore numbed the minds of the planet's populace, allowing him to easily take control of all the world's technology, knowledge and societies, thus becoming the absolute evil ruler of the world while a returning Number 12 was forced to escape underground as he could not bare to see his invention corrupted. Around this time, Executive Mandark was summoned into the future for an important confrontation.
After returning, Mandark used his new found power to live the ultimate life of luxury, spending the majority of his time lounging in hot tubs and became quite obese, so much so that he needed a grappling hook just to move about. At an unknown point, his old foe Dexter resurfaced as Action Dexter and Mandark devoted his time to stopping his mortal enemy from ruining his dark paradise.When the time traveling Dexters stormed Overlord Mandark's castle, he immediately sent out his robots to destroy them, but when that failed and the Dexters arrived, Overlord Mandark revealed his own counter against the Dexters using his own time machine which summoned young Mandark, Executive Mandark and Braindark to help him defeat the Dexters once and for all. The Dexters and the Mandarks confronted one another while Overlord Mandark and Action Dexter exchanged witty banter, commenting on how this reunion reminded them of old times. The young Dexter however silenced them and demanded to have his core returned. The Mandarks and the Dexters then faced off against their respective time counterparts. The young Dexter and Mandark had a rather childish exchange of fisticuffs, Executive Mandark easily overpowered Number 12 due to his weak insecurities, Overlord Mandark and Action Dexter exchanged heavy blows, and Braindark and Old Man Dexter exchanged petty insults.
The One who saved the FutureEventually Action Dexter was able to gain the upper hand by loosening Overlord Mandark's grappling hook, causing him to fall flat on his face. When the Dexters prepared to deactivate the Neurotomic Protocore, each of them were grabbed by their respective Mandark, but before they could deactivate it, Dee Dee appeared from Dexter's Time Machine and all the Mandarks were completely overwhelmed by their love for Dee Dee after seeing their beloved after so long and as she passed by each of them, they could not resist uttering her name with absolute affection. Dee Dee then unknowingly reset the core's flow back to positive after pressing a button. She then happily left the castle and re-entered the time machine while the Mandarks watched her without a care in the world. However as the core began to emit its positive flow, it started undoing all of Overlord Mandark's corruption, and as the Mandarks began to realize the gravity of the situation, they began disappearing back to their own timeline one by one until only Overlord Mandark remained. As the Overlord's body could not handle the positive flow, he let out a powerful "no" before his body finally exploded, leaving behind only his disembodied brain.
After his defeat and the loss of his body, Action Dexter apparently decided to spare his former rival and kept his brain alive in a special jar where he would remain imprisoned for his crimes against the world. At an unknown point, Mandark's brain, now dubbed "Braindark", would be placed inside of the Dexter Museum for all to see and serve as a reminder of the once mighty overlord and his fall at the hands of Dexter. Braindark spent his miserable days constantly swearing vengeance against Dexter and would briefly get his chance when summoned by his past self to fight Old Man Dexter, although in the end he was still defeated and was likely placed back in the museum to wallow in his anger and swearing to someday get back on his feet.
Television film appearance
Video game appearances
Dexter is Mandark's worst enemy. He hates him because he is so much smarter than him and he is always trying to destroy him so that he can be the smartest genius around.
Dee Dee is Mandark's love interest, and is obsessed by her, and if he looks at her he would say, "Dee Dee..." but it hasn't been shown that Dee Dee pays attention.
Also known as Olga, Lalavava is Mandark's sister. She is way younger and smaller than him, but she takes total control over him because she is stronger and more intimidating than him. She always scares and abuses him to make him do whatever she wants.
Oceanbird is Mandark's mom. She does not understand his craving for evil and she wants him to always be nice the same way she is.
Mandark's father, Windbear is always trying to quench Mandark's craving for fighting and evil.
Ducky is Mandark's pet lab duck. Ducky has a supervillain identity known as Quackor that Mandark is unaware of and she always goes out to do evil whenever there is a full moon and Mandark's not around. In the episode "A Quackor Cartoon", Quackor fell in love with Monkey who was Dexter's pet lab monkey. Mandark was in shock to see this and he fainted along with Dexter.
- Mandark's voice actor is Eddie Deezen in the series, but in Cartoon Network: Punch Time Explosion, it is Keith Ferguson, who did the voice of Danny Phantom in Nicktoons MLB.
- The surname Astronomonov would imply that he is Russian. Mandark may also be Japanese, as his mother is based on Yoko Ono and he resembles a stereotypical Asian boy.
- Mandark's age is never mentioned in the series, however it is implied that he is 2 years older than Dexter according to a reference from the Ego Trip concept art (unlockable in the Dexter’s Lab PSX Game) where Executive Mandark’s reference sheet reads “Age 24?” while Number 12 is credited as “D22”.
- In the song "Love According to Dexter", Dexter is said to be 8 years old, which would mean that Mandark is 10 years old.
- In earlier episodes, Mandark's laboratory has a high-tech and more advanced appearance. In later episodes, his lab starts to have a more gothic and crude look.
- In the first two seasons, Mandark did not wear a tie and his head was shaped like a light bulb. In the next two seasons, he did wear a tie and his head was more square shaped.
- In the episode "Dexter's Rival" Mandark had the ability to read minds; this ability was not used or mentioned again throughout the rest of the series.
- In Punch Time Explosion XL, he synergizes with Toilenator.
- It is implied that Mandark's Parents are not married because in the episodes "A Boy Named Sue" and "My Dad vs Your Dad", Mandark was referred to as a lovechild.
- Mandark is the same age as Dee Dee who is in the grade above Dexter and is not in any of his classes. However, he is still seen sitting next to Dexter in his class in "Dexter's Rival".
- In Japanese, Mandark's voice actor is Katsumi Suzuki, who also voices the Red Guy from Cow and Chicken, a fellow Cartoon Network cartoon.
- Mandark seems to speak rather politely and softly in Japanese; this could be to either make him sound more sophisticated, or to make him sound more traditionally Japanese.
- Eddie Deezen has stated that Mandark looks like a caricature of himself, and may be based on Malvin from WarGames.
- Mandark shares many similarities with Mojo Jojo Both are evil geniuses, who take pride in their intelligence, and have a laboratory in their lair. They also both possibly japanese and speak with japanese accents. They both have a personal grudge against the main protagonist, and are their biggest enemies. Mandark becames more similar to Mojo in later seasons, with the sharp eyes and cape, and desire to rule the world.