Chum Chum is Fanboy's best friend and sidekick. Although he is younger than the other main characters, he is still in the same class as them. Show creator Eric Robles explained on the Nickelodeon message board that this is because Fanboy snuck him into his class and the teacher never noticed the age difference. Chum Chum is extremely energetic and high-spirited, and possesses an indomitable enthusiasm and childlike jocularity. Chum Chum has brown hair, and wears an orange and yellow uniform, with white briefs worn outside his costume. In the pilot from Random! Cartoons, Chum Chum wears an orange collared shirt with yellow buttons on the chest instead of his logo. Voiced by Nika Futterman. In the pilot from Random! Cartoons, he was voiced by Nancy Cartwright.

His family comes from the tribe known as "Chulks" from the country of Chulkistan. His cousins and "Chuncle" Joe are Chulks just like him. Chum Chum currently lives and has lots of fun as a roommate with Fanboy. As he is quite short, he learns that being the smallest person is sometimes fun.

As Fanboy's best friend, Chum Chum is always full of fun. Chum Chum is easily fooled, and seems to like chocolate covered raisins, and he has a squeaky voice. Yo likes him, because he is 'Adorable', 'Cute', And 'Chum Chummy'. Fanboy doesn't like this, but feels sorry for her sometimes.

and hates being the smallest person. However, Chum Chum knows that he is not the only small person. He also has a cousin, Muk Muk, who is the same size as him and looks slightly like him, but talks with a weird accent. Chum Chum can also stretch out really tall, like he's standing strong.

Chum Chum is always smarter than Fanboy, and points out the stronger thing than what he said. He even looks up to Fanboy at times, and hopes he's just like him.

He is also loyal and will always stand up for Fanboy no matter what.

Chum Chum is short and chubby, with peach skin. Like Fanboy, he has a blush on his cheeks, but a little more pale. He has dark brown hair with bangs swoopt to the left. There are two parts at the top, that curl away from each other. His right front tooth in his upper jaw is slightly 

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