Leonin Relic-Warder is a uncommon Creature — Cat Cleric card from Mirrodin Besieged (MBS), collector number 10. Current market price: $0.30 (foil $8.16), TCGplayer market prices via Scryfall.
When this creature enters, you may exile target artifact or enchantment. When this creature leaves the battlefield, return the exiled card to the battlefield under its owner's control.