Zygon Infiltrator is a uncommon Creature — Alien Shapeshifter Soldier card from Doctor Who (WHO), collector number 63. Current market price: $0.27 (foil $0.34), TCGplayer market prices via Scryfall.
Body-print — {2}{U}: Tap another target creature and put a stun counter on it. This creature becomes a copy of that creature for as long as that creature remains tapped. Activate only as a sorcery. (If a permanent with a stun counter would become untapped, remove one from it instead.)