Agent Frank Horrigan is a rare Legendary Creature — Mutant Warrior card from Fallout (PIP), collector number 89. Current market price: $3.33 (foil $9.67), TCGplayer market prices via Scryfall.
Trample Agent Frank Horrigan has indestructible as long as it attacked this turn. Whenever Agent Frank Horrigan enters or attacks, proliferate twice. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there.)