Senior at Attic High and unwitting half-goat mutant. Naturally feels like an outsider, even before the transformation. Changes hairstyle daily thanks to rapid hair growth.
Adventurous junior high schooler and brother to Cass. After being turned halfway into a flying squirrel, Flint pushed his mutation further in order to be able to glide.
Senior at Attic High and son of the world's greatest living geneticist. He turned Cass and Flint into animals in an attempt to win Attic High's genetics competition. He's since owned up to the consequences and promised to help them change back.
Senior at Attic High who specializes in taking big leaps without thinking ahead and making dramatic entrances. His imperfect genetic formula is gradually turning him into a salamander.
Four-armed senior at Attic High. Highly emotional if the right buttons are pushed.
Possibly the smartest senior at Attic High. He's made it to the top of the class despite a language deficiency. Prefers to stay silent.
Morty's lab-grown catgirl assistant. She's slowly learning about the human world and her place within it.
Mild-mannered senior at Attic High. Her genetics project involves teddy bears somehow.
Founder and principal of Attic High, the leading private science-focused high school in the country. Is constantly awed and apprehensive about the achievements of her students.