4. The Master - Doctor Who
Just like the Doctor can change his whole body, a new actor is cast for the part, the Master can do the same. Many actors have portrayed The Master throughout the legendary 50 years Doctor Who has been on. Today, however, we only speak about one version of The Master, and that's the John Simm version. John Simm's Master is clever, hilarious, and just outright insane. It's excellent to watch him push The Doctor to his limits without so much as batting an eye. Tricking humans into turning into death robots and then sending them back in time to kill themselves as humans in the past IN A HUGE PARADOX STORYLINE AND HONESTLY just watch the show if you don't already.