Humplings

The Humplings are a group of cartoonish and whimsical beings who inhabit the planet "Rumbledy-Hump". They were first introduced in season 6, episode 8, when Leela is trying to write a story to entertain the orphans after her first attempt failed. She "Invents" the characters Lady Bugle, Fethernoos, Doing, Princess Num-Num and Garbly. She gives them all different characteristics, and they sing moralistic songs in order to teach children lesson. Later in the episode, we figure out the the Humplings weren't of Leela's imagination, but actual beings which Leela used as her Characters.