Adventure Time (S01E19)

Episode #019
'The Duke'
Season 1, Episode 19

Princess Bubblegum hates the Duke of Nuts. I mean, REALLY hates him. When Finn and Jake are outside the castle throwing magic bottles, one of them accidentally smashes through a window and hits PB, turning her bald and green. She believes this was perpetrated by the Duke, and sends Finn out to get justice on him, which fills him with guilt.

Although there are some weird moments and it isn't overall one of the more memorable episodes, Princess Bubblegum reveals herself to be incredibly petty and kind of psychotic here in a way that really helps flesh out her character as much more than just a sweet princess who practices science. The fact she is able to be filled with this much hate for a character who hasn't really done anything to her is kind of funny and shows how flawed she is, just like everyone else. As a character, The Duke is pretty dull, and the episode is basically fluff, but the side plot involving a deranged squirrel seeking revenge on Jake is funny and helps it stand out. All-in-all, this isn't an episode that will leave much of an impression, but it's pleasantly harmless.