Defender

Khalai Reaver enters the battlefield with a scarab counter on it. If you cast it, it enters the battlefield with an additional scarab counter on it.

Whenever Khalai Reaver blocks, you may remove a scarab counter from it. If you do, Khalai Reaver deals 3 damage to target attacking creature.

{3}, {t}: Put a scarab counter on Khalai Reaver.