Pack Rat is a rare Creature — Rat card from Return to Ravnica (RTR), collector number 73. Current market price: $3.06 (foil $3.93), TCGplayer market prices via Scryfall.
Pack Rat's power and toughness are each equal to the number of Rats you control. {2}{B}, Discard a card: Create a token that's a copy of this creature.