Zombie Trailblazer is a uncommon Creature — Zombie Scout card from Torment (TOR), collector number 89. Current market price: $0.91 (foil $12.82), TCGplayer market prices via Scryfall.
Tap an untapped Zombie you control: Target land becomes a Swamp until end of turn. Tap an untapped Zombie you control: Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)