Decimator Beetle

Oracle Text

When Decimator Beetle enters the battlefield, put a -1/-1 counter on target creature you control.

Whenever Decimator Beetle 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.

Card Rulings

4/18/2017 Decimator 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.
4/18/2017 If one target of Decimator Beetle’s second ability becomes illegal, the other will still be affected.