Silkguard is a mythic Instant card from Marvel Universe (MAR), collector number 37. Current market price: $4.06 (foil $6.06), TCGplayer market prices via Scryfall.
Put a +1/+1 counter on each of up to X target creatures you control. Auras, Equipment, and modified creatures you control gain hexproof until end of turn. (Equipment, Auras you control, and counters are modifications.)