Invader Zim
Attack of the Saucer Morons / The Wettening
S1 E5:
Out on a routine information-gathering flight, Zim crash lands the voot cruiser in a field. While Zim goes back to the house to acquire a transport for the damaged cruiser, The Children of the Bright and Shining Saucer (a group that seek aliens) find the ship and immediately hail it as proof of alien life. / It's a rainy day at school but there'll be no fun indoor games for Zim. Zim, it turns out, is deathly afraid of water. Dib immediately uses this knowledge to his advantage and starts a full-scale water war.