When a television, literature, movie, or anime/manga series goes so far off the rails that it's almost as if the creator is trolling internet fansites, hungry for ideas.
Se also Jump The Shark
Magnificent Bastardo just killed his trusted lackey for failing him in a game of hop-skotch? Corporal FlameHappy has a soft spot for kittens? The hero's mother was a SHEEP!?
Damn you! *Authors Name* has Trolled My Fandom!