In the film, he kidnaps all the children's parents from Retroville and tried to feed them to Poultra, a humongous alien chicken whom he and his people worshipped for centuries. He was aided by his majordomo, Ooblar and although he tried to off Jimmy and his friends after they rescued their parents, Jimmy grew to a huge size and defeated him.
In the TV series, King Goobot arrives on Earth and pretends to be nice to the citizens and even invite the citizens to the party, but Jimmy suspects something about Goobot's scheme. Later, he steals one of Jimmy's inventions to revive Poultra and traps the citizens as he tries to feed them to Poultra, but Jimmy puts some Purple Flurp in Poultra's water bowl and Poultra explodes after burping. Goobot then goes back into space in a giant eggshell spaceship along with the other yokians and Ooblar before the citizens apologize to Jimmy.
King Goobot is also the leader of the League of Villains, whose goal was to get revenge on Jimmy Neutron. He was later trapped in the Cretaceous period along with the other antagonists, and remained there.
Role in the series
King Goobot is an independent villain of which has been wanted by the Galactic Federation for years for crimes such as kidnapping aliens and feeding them to Poultra. The Grand Councilwoman views him as quite a nasty and gross criminal, and has even stated that he met the criminal when he had a crush on her. Yet Vainiana responded by sending him to jail, only for him to escape thanks to efforts from Ooblar. He is still wanted to this very day, yet he is protected in his kingdom from them by their superior defenses. He was even a former candidate for the Villain League, but his ultamate reason for not getting involved is because his kingly duties conflict with Villain Team membership, along side keeping Poultra well fed.