The Twelfth Doctor encountered this dream version of Santa in 'Last Christmas'. He was the product of the dream crabs - clawlike creatures that latch on a human head and feed on people's brains while putting them in a dream state.

Karvanista was a dog-like alien who was the last surviving member of the Division, a Time Lord 'special forces' group that intervened to protect Gallifrey. He was effectively the Fugitive Doctor's companion. During the Flux he was bonded with Dan Lewis, and kidnapped him in order to save him.