Uncle found himself on House when a temporal rift caused him to be transported there. On the asteroid, he lived with Auntie, Nephew and Idris. Like Auntie, he was made mostly of body parts snatched from Time Lords and other creatures that were also transported to House. He had a rather sombre disposition, and tended to make dark jokes and surly remarks.
He and Auntie died when House left the asteroid as they both relied on it for their life functions. Faced with their imminent death, Uncle and Auntie were stoic and unfazed, though Uncle admitted that he was "against it". He died shortly after Auntie, declaring, "Actually, I feel fine", before suddenly collapsing dead.
The Doctor noted that he had the eyes of a twenty-year-old, but that the rest of his body was thirty years older. Aside from the eyes, by the time he died, he had an alien right ear, his right arm was two inches longer than the other, and he had two left feet. At some point in the past, he had acquired the Corsair's spine and kidneys after House had lured him onto the asteroid. (TV: The Doctor's Wife)