Cheapest priced copy (Amonkhet): $0.35 at Card Kingdom, near mint, their price list as of .
Decimator Beetle 
Creature — Insect · 4/5 · Uncommon · Amonkhet · #197
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.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Amonkhet | 197 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 18 April 2017Decimator Beetle’s second ability can target any creature you control, not just one with a -1/-1 counter on it. It’ll put a -1/-1 counter on the opponent’s creature even if there isn’t one to remove from your creature.
- 18 April 2017If one target of Decimator Beetle’s second ability becomes illegal, the other will still be affected.