Altered Ego is a rare Creature — Shapeshifter card from Shadows over Innistrad Promos (PSOI), collector number 241s. Current market price: — (foil $4.42), TCGplayer market prices via Scryfall.
This spell can't be countered. You may have this creature enter as a copy of any creature on the battlefield, except it enters with X additional +1/+1 counters on it.