Coral Trickster is a common Creature — Merfolk Rogue card from The List (PLST), collector number DDN-44. Current market price: $0.29, TCGplayer market prices via Scryfall.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, you may tap or untap target permanent.