Sewerdreg is a common Creature — Spirit card from Ravnica: City of Guilds (RAV), collector number 104. Current market price: $0.05 (foil $0.35), TCGplayer market prices via Scryfall.
Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.) Sacrifice this creature: Exile target card from a graveyard.