The Corsair

The Corsair was a Time Lord described by the Eleventh Doctor as "one of the good ones". His signature emblem was a classical depiction of the mythological Oroborus, a snake devouring its tail. According to the Doctor, he had a copy of the emblem tattooed onto his body after each regeneration even when he regenerated as a female. Without it, the Corsair didn't feel like himself/herself. In his last known regneration, the tattoo appeared on the inside of his left forearm.

The Doctor described the male Corsairs as "hell of a bloke" and the female Corsairs as "a bad girl!".

The Corsair was presumably killed by the entity known only as House, a disembodied being that fed on artron energy it harvested from captured TARDISes. The Corsair's left arm had been stitched onto the composite humanoid creature being known as "Auntie" that served as House's slave while the other composite humanoid creature slave "Uncle" received "the spine and the kidneys". The loss of these organs was presumably lethal and the Corsair went the way of House's numerous other Time Lord victims.

The final incarnation of the Corsair was described by Auntie as "a strapping big bloke". The Doctor discovered his fate after being contacted by his hypercube and following its psychically encoded distress message to House. The Doctor became enraged by this revelation, and threatened the Corsair's killers, saying that giving someone hope then taking it away is enough to make anyone dangerous. (DW: The Doctor's Wife)