Foster's Home for Imaginary Friends (2004)

S02E12 Bloo Done It

Bloo grows wary when Uncle Pockets, a former "friend" of the house, makes a surprise comeback after being away for quite some time. His sudden reappearance raises red flags for Bloo, who can’t shake off the feeling that something isn’t quite right. As he investigates Uncle Pockets' intentions, his curiosity leads to unexpected revelations that might change everything in the house.