Caterpy is a caterpillar-like humanoid alien that Son Goku fights in the tournament of the episode "Tournament Begins." He is from the South Quadrant of the Other World. Caterpy is not actually very strong and he tries to get Goku to give up by tickling him in a torture. After Goku hits him, he shows his weakness more by whining about it. Caterpy would then get mad enough to go into his pupa state. As South Kaiō tells Goku and the crowd, Caterpy would morph into his ultimate form upon hatching. However, the cocoon would take 1,200 years for everyone to wait so Dai Kaiō would then declare Goku the winner by default.
He may have been named after the Pokemon of the same name.