One thing that cracked me up so much was Third Rock from the Sun which first had the big giant head, played by William Shatner. He got off a plane and was talking about his trip and said he looked out the window and saw something on the wing. And Dick, played by John Lithgow, says the same thing happened to him. Hilarious cause Shatner was in the original episode with the gremlin on the wing (Nightmare at 20,000 Feet) and John Lithgow played the character in a remake for the Twilight Zone movie.
Note: You can see it in the beginning of this clip on YouTube for what I'm referring to:
