Hat Trick is a common Instant card from Unfinity (UNF), collector number 13. Current market price: $0.08 (foil $0.12), TCGplayer market prices via Scryfall.
Target blocking or blocked creature you control gets +1/+1 and gains first strike until end of turn. If it has a hat, it gains double strike until end of turn. If you and that creature each have a hat, the creature gains triple strike until end of turn.