Coco is one of the tritagonists of Foster's Home for Imaginary Friends, and is voiced in English by voice actress Candi Milo.
Coco is kind, helpful, funny, ditzy and surprisingly sarcastic, despite the fact she only says one word. Coco has a palm tree for a head, a crooked red beak, a blue and white aeroplane body, and orange legs. Coco's creator, according to a golden trading card in the Foster's Home For Imaginary Friends Leapster game, is created by a girl who crashed on a desert island, which could explain her appearance of the palm tree head and airplane body. She was discovered by two scientists named Douglas and Adam (called "nerds" by Bloo), who were introduced in "Good Wilt Hunting." Since they found her alone, it's never been stated or known what became of Coco's original creator. Although Coco has attempted to tell Douglas and Adam, they may have either unintentionally ignored her or not understood what she was trying to say. Throughout "Good Wilt Hunting," it's shown that she acts as a motherly figure towards Douglas and Adam. She is 4 feet tall and weighs 80 pounds.
Her only verbal utterances and written means of communication is "coco" (with each syllable pronounced "co"), which most of the imaginary friends, Mac, Frankie, Madame Foster, and other characters can seemingly understand. This can lead to strange conversation, such as in "House of Bloo's", when Bloo repeatedly said 'yes' every time Coco said "coco?" (because he thought she was asking him if he wanted hot chocolate), until Wilt explained that that's all she ever says. When Bloo asked what she was really asking them, Wilt replied "Do you want any juice?"
She also has had to be heard by many people in "Hiccy Burp" (taking over for Wilt as the talent show pageant's host due to Wilt's mistakes), and in "Store Wars", she used the mall's intercom to alert security guards and shoppers. Also in "Cuckoo for Coco Cards", she led Mac's classmates on a tour of the home, implying that they understood her.
She is usually understandable to all, but may not be, depending on what jokes are needed. She also seems unable to write anything but "Coco," with similar rules applying to whether or not people can read it (Mr. Herriman once read a ransom note from her in "Crime After Crime", but was unable to figure out who sent it despite the obvious clue and when Mac read her diary in the episode "Squeeze the Day", he was unable to decipher it.) In the episode "The Big Picture", one of the clues Bloo thought to why all the imaginary friends disappeared on one of the annual group photos (and all of his ideas were very unlikely, including this one) was when Coco actually said something besides "Coco," (namely "Cheese!") which caused everyone to run off.
Coco is friends with the imaginary friend Sassyfrass as seen in "Partying is Such Sweet Soirée". In the same episode, she has been shown to be romantically involved with a lamp. However, the lamp was tragically broken by Mac in a sugar rush during the episode, until she taped it back together.