Buy @ TCGplayer
Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.
Changeling applies in all zones, not just the battlefield.
If the target creature is an illegal target by the time Crib Swap tries to resolve, the spell won't resolve. No player will create a Shapeshifter token.
Tribal is a card type (like creature or instant), not a supertype (like legendary).
