Thomas Wheeler is a half-blood, the eldest of three children born to a wizard father and muggle mother, and was raised in Edinburgh. His father, William Wheeler, comes from a wizarding family of some renown, whilst his mother Mila is a doctor. Despite the secrecy between the two worlds, Tom's parents are proud of their heritage, and their children are on good terms with both their magical and non-magical relatives.

Thomas has his father's height, tending toward lanky in the way that already-tall eleven year old children do in advance of a teenage growth spurt. In every other way, however, he is his mother's son; from the Slavic cheekbones and narrow features, to the dirty blonde hair and blue eyes that they have in common.

Taciturn by nature, Thomas opens up more in familiar social surroundings than he does in larger groups. This doesn't mean he has difficulty making friends - in fact, given that he isn't generally difficult to get along with, he tends to fit well with most people. That said, when it comes to holding grudges he could be considered a professional, and often there's no changing his mind once he decided he doesn't like someone. In private, among friends, he can be quick-witted and glib; a trait which occasionally leaches over into situations where it isn't appropriate.