Cathars' Crusade + Devoted Druid + Hapatra, Vizier of Poisons

WBG identity

Commander legal

The 3 combo pieces

What must be in place

Devoted Druid does not have summoning sickness.
Devoted Druid does not have a -1/-1 counter on it.

How to execute it

  1. Activate Devoted Druid by tapping it, adding {G}.
  2. Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
  3. Hapatra triggers, creating a 1/1 Snake creature token.
  4. The Snake enters the battlefield, triggering Cathars' Crusade, putting a +1/+1 counter on each creature you control.
  5. Repeat.

What the combo produces