Bill Potts is a rare Legendary Creature — Human card from Doctor Who (WHO), collector number 379. Current market price: $0.15 (foil $0.19), TCGplayer market prices via Scryfall.
Whenever you cast an instant or sorcery spell that targets only Bill Potts or activate an ability that targets only Bill Potts, copy that spell or ability. You may choose new targets for the copy. This ability triggers only once each turn. Doctor's companion (You can have two commanders if the other is the Doctor.)