King Thingg is a well respected ruler of Mars, and can be comical often getting into hilarious mishaps. However, it's revealed he's paranoid at invasion and often jumps to conclusions as he starts the invasion of Earth to stop the supposed invasion of Mars, whilst he was easily mislead and lied too when an inept, martian scientist had made this out to be a horrific thing to him and his own people, when it really isn't.
King Thingg appears as the ruler of Mars and initially praises Jerry believing him to be a god named "The Great Gloop". However, after Tom accidentally destroys the Martian city due to his clumsiness and large size (in fairness, Tom tried to be gentle in terms of greeting himself to the martians who misunderstand him as a vicious giant, leading him feeling horrified and tried to help out), he attempts to burn Tom alive in a fiery pit and have him eaten by a monstrous predator as the Martians, Jerry and Peep are forced to watch. As Tom and Jerry both get exposed as Earthlings, he plans to execute them and start an invasion on Earth in order to prevent Mars from being invaded, even when it means to discover whether there is life on Mars or not, only for the sake of protecting his race out of overprotectiveness. This leads to Peep to betray him and save Tom from death before joining the cat and mouse duo to make peace between Earthlings and martians. He first starts off by sending a squad of Martians to Earth, having them equipped with disintegraters, and then an advanced giant robot called the Invincatron as a back-up. It is unknown what happened to him after the Invincatron was defeated, but it is supposed that he left Earth alone as the loss of the robot proved to be too much for Mars to handle.