Here’s a 1962 clip from the sitcom Mr. Ed, featuring a guest appearance by Clint Eastwood. What’s interesting is that Eastwood portrayed himself in the episode. He was starring in Rawhide on CBS at the time (Mr. Ed was a CBS show too), and this episode is titled “Clint Eastwood Meets Mr. Ed.”
Eastwood also appeared in the 1955 comedy Francis in the Navy, which featured a talking mule.
[via Reel Life with Jane]