For Disney, besides playing Ernest P. Worrell in the Ernest film trilogy, he is also known for providing the voice of Slinky in the Pixar films Toy Story, Toy Story 2, and in the video game Animated StoryBook: Toy Story and Toy Story: Activity Center. He also voiced Ephialtes in the Hercules episode, "Hercules and the Muse of Dance." Shortly before work began on Toy Story 2, Varney was diagnosed with lung cancer and died, while he was recording lines for another Disney film Atlantis: The Lost Empire, which was released a year after his death. In Toy Story 3, his friend, Blake Clark took over as the voice of Slinky. Clark will likely reprise the role in Toy Story 4.
- Jim was good friends with comedian Blake Clark in real life. In an interview for Toy Story 3, Clark described Varney as a very good friend and man.