Gumball's Brain

Gumball's Brain is a minor character who appears in "The Genius". He is used by Gumball for thinking and, apparently, he has signed a contract with him. He also is mentioned in "The Banana." He returned in Season 3 in episode "The Coach," telling Gumball's whole body to panic because Gumball is exercising.

Appearance
In Season 1, Gumball's Brain looks like a typical animated brain with big dark blue eyes, eyebrows, two thin arms and legs, and a mouth. Meanwhile in Season 2, he is redesigned to look like a normal brain in "The Bumpkin."

Season 1

 * "The Genius": First major role.
 * "The Party" (Mentioned)

Season 2

 * "The Banana" (Mentioned)
 * "The Bumpkin"
 * "The World": Second major role.

Season 3

 * "The Coach"
 * "The Name"
 * "The Recipe"
 * "The Fraud"

Trivia

 * Although it is Gumball's brain, Gumball was able to think without it. It also seems that Gumball is more intelligent than his own brain as he was "teaching" it how to be smart.
 * Anais thought that his brain would be smaller due to Gumball being very dumb, even though it has been proven that brain size is not related to intelligence.
 * He appeared to be much bigger in "The Bumpkin."
 * A similar brain wearing a hat can be seen in "Halloween" at the house party.