Fertilid + Crystalline Crawler + Avenger of Zendikar + Ancient Greenwarden + Xenograft

Fertilid

Crystalline Crawler

Avenger of Zendikar

Ancient Greenwarden

Xenograft

How it works

1. Activate Fertilid by paying 1 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 1.
4. Repeat.

This intricate loop transforms a simple land-search into an overwhelming board state by turning your entire team into a self-sustaining engine. With Xenograft declaring Elementals (or Plants) as the universal creature type, every single creature you control—including Crystalline Crawler and Fertilid—benefits from the counters distributed by Avenger of Zendikar. When Fertilid fetches a basic land, Ancient Greenwarden doubles that landfall trigger, allowing Avenger of Zendikar to flood your board with double the +1/+1 counters to fuel Crystalline Crawler's mana-producing ability and keep the cycle spinning.