Robin Hood

Look at him. He regrets nothing.
Robin Hood and his Band of Merry Morons.

Robin Hood was a fictional character in some story book from like a hundred years ago or something that was adapted into a bunch of films, notably one by Disney. Despite being a fictional character, he was canonised in September of 2014 by Mark Gatiss when Steven Moffat needed a 13th episode for the series. Robin Hood is known to be a complete scoundrel who leeches off the tax welfare system, only to rob rich people for even more of their precious money, whilst evading the justice system. The Doctor met him one time and was absolutely disgusted by his criminal behaviour, turning him into evil robots who hung him in public for his many heinous crimes. Somehow, he escaped this execution, murdered some of the kingdom's authority figures and went on his way, returning to his gang of criminals. Finally, his criminal activity was ended when the Canon 9th Doctor came back in time with his assistant Baldrick and convinced Robin's Merry Men to execute him.

Robin Hood in the moments before his death.
The Doctor seemed to have forgotten that he was once Robin Hood.

Notes

  • There was a BBC series airing during the Tennant era, starring Patrick Troughton's grandson, that was for all intents and purposes the BBC family drama show that aired while Doctor Who was off-season. It was kind of comfy for two seasons. But then they killed Maid Marian, everyone including the showrunners started dropping the show, and it got replaced with Merlin.