Slumbering Keepguard is a common Creature — Human Knight card from Wilds of Eldraine (WOE), collector number 29. Current market price: $0.23 (foil $0.33), TCGplayer market prices via Scryfall.
Whenever an enchantment you control enters, scry 1. {2}{W}: This creature gets +1/+1 until end of turn for each enchantment you control.