Mizzium Skin is a common Instant card from Return to Ravnica (RTR), collector number 45. Current market price: $0.21 (foil $0.67), TCGplayer market prices via Scryfall.
Target creature you control gets +0/+1 and gains hexproof until end of turn. Overload {1}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")