Decimator Beetle is a uncommon Creature — Insect card from Amonkhet (AKH), collector number 197. Current market price: $0.08 (foil $0.37), TCGplayer market prices via Scryfall.
When this creature enters, put a -1/-1 counter on target creature you control. Whenever this creature attacks, remove a -1/-1 counter from target creature you control and put a -1/-1 counter on up to one target creature defending player controls.