Why Hippo Has No Hair

S1, E16: There was a time when Hippo did have hair, lots of hair! She was always unbearably hot. Then one hot night while Hippo was sleeping, a spark from the fire caught the end of her hairy tail. Hippo was on fire, and she ran through the bush until she jumped in the waterhole. From then on Hippo stayed in the cool waters without a single hair on her hide.