Michael Gambon 

A horrible actor who ruined the character of Dumbledore in the Harry Potter movies. He has not read the books and yet is somehow permitted to play Dumbledore, which he fails miserably at. He loses his temper at Harry and starts screaming and shaking him, which the real Dumbledore would never do. He also ties his beard in a ponytail.

Michael Gambon made the Harry Potter movies even worse than they already were!

Michael Gambon by the elven archer November 17, 2006