Fertilid + Tiller Engine + Lotus Cobra + Beorn's Hospitality

Fertilid

Tiller Engine

Lotus Cobra

Beorn's Hospitality

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 on the battlefield untapped due to Tiller Engine.
2. When the basic land enters, Tiller Engine, Lotus Cobra and Beorn's Hospitality trigger.
3. Resolve the Tiller Engine trigger, untapping the basic land.
4. Resolve the Lotus Cobra trigger, adding .
5. Resolve the Beorn's Hospitality trigger, putting a +1/+1 counter on Fertilid.
6. Activate the basic land by tapping it, adding 1.
7. Repeat.

This loop transforms Fertilid into a self-sustaining land engine by cycling its counters directly into your library's basic lands. Each time Fertilid uses its ability, it fetches a basic land that enters the battlefield tapped, instantly triggering Tiller Engine to untap it so you can tap it for mana. At the same time, Lotus Cobra generates an extra mana of any color to help fuel the activation cost, while Beorn's Hospitality constantly replenishes Fertilid's +1/+1 counters to keep the loop going.