The Marvelous Misadventures of Flapjack (2008)

S1E25 Lead 'Em and Weep

Concerned that K'nuckles is a negative influence, Bubbie advises Flapjack to stop trailing the pirate and instead take the lead. However, after seeking guidance from an animal trainer, Flapjack inadvertently hypnotizes K'nuckles, causing him to think he’s actually a seal.