Which of these actors does not appear in both of these films "Rebel Without a Cause" and "Giant"?

The actor who does not appear in the two films "Rebel Without a Cause" (1955) and "Giant" (1956) is Corey Allen. Allen was best known for his role as gang leader Buzz Gunderson in Nicholas Ray's film "Rebel Without a Cause".

In the film James Dean starred as Jim Stark. He was a disaffected teenager who had moved to Los Angeles, CA to start a new life. There he found more problems in his new home. After a show at the Griffith Observatory, Buzz challenges Jim to a knife fight. Jim wins the fight by subduing Buzz with a switchblade.

Later Jim is challenged to a car race. The winner will be the last one to jump out. Before Jim and Buzz embark on their death race, they stand at the edge of the cliff, looking down at a deadly fall. Jim questions whether they should go ahead with their race. Buzz responds, "You got to do something, don't you". Buzz is killed during the race. His car crashes on the beach below the cliff.

During the 1950s, Allen's acting career gave him the opportunity to perform in about eleven films, including "Rebel Without a Cause".

The other actors James Dean, Sal Mineo, and Dennis Hopper appear in the films "Rebel Without a Cause" and "Giant". Dean is Jim Stark, Mineo is John "Plato" Crawford, and Hopper is Judy's father in "Rebel". In "Giant, Dean is Jett Rink, Mineo is Angel Obregón II, and Hopper is Jordan "Jordy" Benedict III, Leslie and Bick's son.