Doc Duodenum is a minor villain from the Earthworm Jim series. He was once the duodenum of a gigantic alien entity, but he got bored of his life and then decided to leave on his own (this probably was not very good for the alien). He created his own planet, shaped over his vision of perfection. The planet, the Intestinal Planet, is actually a gigantic intestine. He lives on digesting anyone that comes into his planet, spitting acid on his victims. Earthworm Jim came into his planet while chasing Psy-Crow, so Doc decided to have him for dinner. Jim obviously disliked the idea, and was forced to fight him. Victorious and disgusted, he left the planet. However, Jim needed to cross the planet a second time, so in order to avoid being detected, he used his stealth disguise of Sally, the blind cave salamander, thus being able to squeeze over the intestinal tracts without being noticed by the Doc.