Rona Bellows

Fiona Bellows was an elderly wheelchair user. While waiting for Christmas dinner, she was attacked by a dream crab. In her dream state, she thought she was a scientist and a professor at the North Pole on Christmas Eve and had use of her legs. She was able to wake up from the crab-induced dream, killing the alien creature in the process, with the help of the Twelfth Doctor and Santa Claus. (TV: Last Christmas)