Requires

Fertilid must be on the battlefield. Crystalline Crawler must be on the battlefield. Avenger of Zendikar must be on the battlefield. Ancient Greenwarden must be on the battlefield. Maskwood Nexus must be on the battlefield. Fertilid has at least one +1/+1 counter on it. Mana needed:

Steps

1. Activate Fertilid by paying and removing a +1/+1 counter from it, causing you to search your library for a basic land card and put it onto the battlefield tapped.
2. When the land enters the battlefield, Avenger of Zendikar's second ability triggers twice, putting two +1/+1 counters on each creature you control.
3. Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding .
4. Repeat.

Results