Wallace Shawn

Wallace Michael Shawn (born November 12, 1943) is an American actor, voice artist, comedian, playwright and essayist, best known as the voice of Rex in the Toy Story franchise. Some of his other roles include Vizzini in The Princess Bride and Dr. John Sturgis in Young Sheldon.

For Amphibia, he voiced actor Humphrey Westwood in the third season "Hollywood Hop Pop".