Mandible Justiciar is a common Artifact Creature — Phyrexian Cleric card from Phyrexia: All Will Be One (ONE), collector number 21. Current market price: $0.19 (foil $0.24), TCGplayer market prices via Scryfall.
Lifelink Whenever another artifact you control enters, this creature gets +1/+1 until end of turn.