O is for... Odin

Leader of a Mire raiding party who impersonated the Norse deity in order to manipulate a small Viking community. Like the mythical figure, he wore an eye-patch. The war-like Mire preferred to let their reputation for bloodshed overpower a target population, to avoid actual conflict. Warriors were their chosen victims as they thrived on certain male hormones such as testosterone. 

After a huge projection of his face appeared in the sky above the Norse village, a party of Mire descended from their orbiting spacecraft and lured the best warriors up to it - claiming they were being taken to Valhalla. Once aboard, they were vapourised and their hormones harvested. The ship was about to depart when a girl named Ashildr challenged the Mire to a fight. Odin was forced to accept, conscious of their reputation, but also because their advanced weaponry would make short work of the remaining villagers.

However, the Doctor was also aware of their reliance on reputation and so set up a trap - tricking Odin and the Mire into thinking they were being attacked by a dragon when in fact they were only being confronted by a wooden mock-up. This was filmed, and the Doctor threatened to release the footage galaxy-wide to shame Odin and his warriors - forcing them to depart.

Played by: David Schofield. Appearances: The Girl Who Died (2015)

• Schofield stepped in late in the day to play Odin when the original actor fell ill - Brian Blessed.
• Usually cast as policemen or criminals, one of his best known roles involves neither side of the law. He is the patron of "The Slaughtered Lamb" - the country pub in An American Werewolf in London - who is prepared to tell the psychiatrist (John Woodvine) what really happened to the two US hikers.