The Cleveland Show - Season 2 Episode 18
The Essence of Cleveland

When Cleveland is reunited with his former high school classmate, "Fatty Patty," who is now skinny, beautiful and still has a crush on Cleveland, Donna becomes extremely jealous and wary of Pattys motives for wanting to be friends with Cleveland. Patty turns out to be a little crazy, and after she tries to steal Clevelands "essence," Donna goes on the hunt to stop her.