TenNapel began as an animator on "Attack of the Killer Tomatoes: The Animated Series". He soon began working in the video game industry on projects like 1993's "Jurassic Park" and "The Ren & Stimpy Show: Stimpy's Invention" for the Sega Genesis and "The Jungle Book" for the SNES and Sega Genesis. In 1994, he created Earthworm Jim, the character that would star in Shiny Entertainment's video game, toy line, and cartoon series. Shiny Entertainment head David Perry later commented on working with TenNapel, "I wish I could find 100 Dougs, then I realized I was lucky to have been able to work with one. He is crazy talented, both crazy and talented! He also generates an enormous amount of amazing content and ideas, I wouldn’t be surprised if he sleeps with a sketch-book!" In 1995, he left Shiny Entertainment and founded his own company, Neverhood, with several other former Shiny employees. Working for DreamWorks Interactive, Neverhood created "The Neverhood" for the PC and PlayStation. The sequel, entitled "Skullmonkeys", followed in 1998.