Tyrant

Tyrant was among the insults which the Sixth Doctor applied to Astrolabus. (COMIC: Once Upon a Time-Lord)

Garron recalled that Graff Vynda-K, once Emperor of Levithia, was a tyrant. (TV: The Ribos Operation)

The Fourth Doctor described Xanxia as "the tyrant queen of Zanak". (TV: The Pirate Planet)

Nyssa recognised the Master, whom murdered her father, as a tyrant. For this reason, she resisted Monarch's tyranny. (TV: Four to Doomsday)

The Great Intelligence presented the Doctor's TARDIS on Trenzalore, where the Eleventh Doctor originally fell, as the "final resting place of the cruel tyrant". (TV: The Name of the Doctor)

Will Scarlet, of Robin Hood's Merry Men, described King John of England, who ruled England in his brother's stead, as a tyrant. Robin himself described the Sheriff of Nottingham as a tyrant. (TV: Robot of Sherwood)

In 5080, Calbaron III was ruled by the tyrannical emperor Vimlox until the Twelfth Doctor overthrew him. (COMIC: Planet of the Diners)

In a timeline glimpsed by a continuity bomb, the Tenth Doctor allowed Wilfred Mott to die in the Immortality Gate. The Doctor eventually embraced the title of "Time Lord Victorious" and became a mad tyrant who ruled over time and space before a Raxacoricofallapatorian shot him, firing a gun that cancelled the regeneration process. (COMIC: Four Doctors) Likewise, one possible account of the Doctor's future showed him becoming the Emperor, (PROSE: Father Time) a cruel tyrant who ruled the universe before he was assassinated. (COMIC: Miranda)