TV Characters Who Vanished From Their Shows

Kenny, South Park

They killed a kid. They really did that. He was blased by an alien spaceship, trampled by a herd of cattle, then run over by a police cruiser.

When filming Chinatown Jack Nicholson was dating Anjelica Huston, the daughter of his screen nemesis John Huston.
The skeletons in "Poltergeist" are not props. They are real human skeletons.
During the filming of The Grinch, Jim Carrey sought counseling from a Navy SEAL to learn torture-resistance techniques in order to handle the extensive makeup.
Director Steven Spielberg made his first film for a merit badge