He replaced the late Jim Varney as the voice of Slinky Dog in Pixar's Toy Story 3 and has become the official and current voice of the character since 2010. He also portrayed a biker in Bedtime Stories. He portrayed Harry Turner in 24 episodes of ABC's Home Improvement. He also had a recurring role in Boy Meets World from seasons 2 to 7 as Chet Hunter. He also played Farmer Fran in The Waterboy. Clark portrayed Uncle Mel in Good Luck Charlie.
- In real life, Clark was good friends with Jim Varney. In an interview for Toy Story 3, he described Varney as a very good man and friend.