Coco was created by a little girl who was shipwrecked on a deserted island after a plane crash.
as having the head is a palm tree, as the child ate coconuts. The beak is a deflated raft as that was the means of transportation onto the deserted island, with the body of an airplane marking the plane she was on and the human feet that were sunburned as the only thing that child saw. She was "discovered" by two scientists, named Douglas and Adam (called "nerds" by Bloo) when that story was told in "Good Wilt Hunting."
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 "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 stage fright), 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, this would imply that they understood her.
Coco is a Sentinel cadet while also still trying to cope on new enviroment in the Safe House.