Blightbelly Rat is a uncommon Creature — Phyrexian Rat card from Phyrexia: All Will Be One (ONE), collector number 435. Current market price: — (foil $0.44), TCGplayer market prices via Scryfall.
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) When this creature dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)