Richard Moll of Night Court fame, in the movie Caveman alongside Ringo Starr
Tony Randall of Odd Couple fame, in the movie The 7 Faces of Dr. Lao
Jack O'Halloran of Superman the Movie fame (as Non, henchman of Zod), in the live-action movie The Flintstones
John Ratzenberger of Cheers fame, in the animated movie Monsters, Inc.