Fertilid + Felidar Retreat + Lotus Cobra + Spelunking

Fertilid

Felidar Retreat

Lotus Cobra

Spelunking

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 Spelunking.
2. When the basic land enters, Lotus Cobra and Felidar Retreat trigger.
3. Resolve the Lotus Cobra trigger, adding .
4. Resolve the Felidar Retreat trigger, putting a +1/+1 counter on Fertilid.
5. Activate the basic land by tapping it, adding 1.
6. Repeat.