Snowball is a genetically altered hamster and the former friend of the Brain who was also the subject of gene splicing.
Snowball's tail is stubby and the same faded orange as his fur. He has jowls, pink eyes, and a large head similar to Brain's. His stomach, unlike the rest of his fur, is white.
He is highly intelligent due to the gene splicing and develops complex plans for taking over the world, though he will at times take Brain's ideas and implement them before he and Pinky are able to. Unlike Brain, Snowball clearly does not have good intentions for the world.
Season 01, Episode 09 "Snowball "
Season 01, Episode 20 "Welcome to the Jungle "
Season 03, Episode 27 "Brain Noir "
Season 03, Episode 42, "A Pinky and the Brain Halloween "
Season 04, Episode 02 "Brainwashed Part 2: I Am Not a Hat "
Season 04, Episode 03 "Brainwashed Part 3: Wash Harder "