Arnold is the cause of two birthday party's for Eugene being a big flop./Stinky feels that he is a failure at everything he does until Arnold helps him discover that he is the best pumpkin grower in town.
Eugene's Birthday: When Eugene's birthday parties are a bust, he begins to think that Arnold is a jinx, and Arnold tries to prove him wrong by throwing a perfect birthday party. Stinky's Pumpkin: Stinky doesn't believe he's good at anything, but when he enters a crop-growing contest, he ends up growing a pumpkin the size of a small building.