Relentless Rats is a common Creature — Rat card from Masters 25 (A25), collector number 105. Current market price: $4.12 (foil $6.67), TCGplayer market prices via Scryfall.
This creature gets +1/+1 for each other creature on the battlefield named Relentless Rats. A deck can have any number of cards named Relentless Rats.