Alex Thompson
Alex was a working-class human. He was the husband of Claire and the adopted father of George.
Biography
Claire was unable to have children. They took IVF treatment, to no avail. Eventually they had son and named him George. When George became frightened of something in the flat, it was placed in his bedroom cupboard. Alex could not cope with looking after him and began to wish someone would take George away. He had no job of his own, most possibly to keep an eye on George, and could not keep up with his rent.
In 2011, the Eleventh Doctor visited per a psychic distress call from George. After George displayed great telepathic powers, trapping him in the cupboard with other, Alex learned from the Doctor that George was a Tenza. Despite this, Alex knew George was still his son. Alex's unconditional love allowed George to overcome his fears and save his father, the Doctor and Rory from the Peg Dolls.
Subsequently, Alex lived a more peaceful life with his family. However, he still worried that George's alien nature may cause something odd to happen to his physical appearance. The Doctor promised to return when George was going through puberty, just in case. (TV: Night Terrors)
Behind the scenes
According to The Brilliant Book 2012, a book that contains non-narrative based information, Alex's scripted last name was Thompson. However, there is no indication of any last name in Night Terrors as originally transmitted.