Don Keith Opper (born June 12, 1949) is an American actor, writer, and producer who has starred in film and on television. He is best known for his role as Charlie McFadden in the 1986 science fiction film Critters and each of the three sequels. His most recent film is in the 1998 film Where's Marlowe?. Opper has made guest appearances on many TV shows, including Miami Vice, Quantum Leap, 21 Jump Street, Roseanne, and The Division.