Cloister Gargoyle is a uncommon Artifact Creature — Gargoyle card from The List (PLST), collector number AFR-302. Current market price: $0.27, TCGplayer market prices via Scryfall.
When this creature enters, venture into the dungeon. (Enter the first room or advance to the next room.) As long as you've completed a dungeon, this creature gets +3/+0 and has flying.