Albert Smithe
Albert Smithe was one of the people attacked by dream crabs. He likely resided in present day London like Clara, as the Twelfth Doctor said that "everyone else was collateral damage" when the dream crabs tracked her down through his memory.
In his dream state, he thought he was a scientist and a professor at the North Pole on Christmas Eve. He attempted to console Shona during the briefing for entering the infirmary, but his attempt was misunderstood as a perverted act. To annoyance, he watched as Shona danced to keep her mind off-limits to the creatures. He along, with the others were sent into a secondary dream state by the crabs when the Doctor and Clara arrived. He made a passive comparison to the film Alien, which the Doctor found offensive and believed to be the reason that real aliens kept invading earth.
After the Doctor saved Clara from a third dream, he helped everyone realize that the base was dream as well. However, Albert got too close to a screen showing the projection of his sleeping self and was killed by it. In the real world, his body died and the fate of the dream crab attacking him was left unknown. (TV: Last Christmas)