12 Movies Where The Hero Became A Villain

9. Scooby Doo

The Hero

He might be one of the most annoying sidekicks in the history of the screen, but Scrappy Doo has always been a good guy who was added to Mystery, Inc to create a new dynamic and save the faltering show from cancellation. It worked, but ungrateful fans still expressed dislike over the years.

But for all his annoying tics - the egotism, the arrogance, the delusions of "Puppy Power" - he's harmless and actually was useful to the team (particularly when he was teamed up alone with Scooby and Shaggy, since he became the brains of the outfit).

But Then...

In the first Scooby Doo live-action movie, it's revealed that Scrappy Doo is in fact the villain, having been kicked out of Mystry, Inc for getting out of control and urinating on Daphne. He plans to sacrifice a pure soul - Scooby - and rule the world for ten thousand years, which is something of an over-reaction to being kicked out of a nerd gang.