When Golgari Rot Farm enters the battlefield, it, Zendikar's Roil, and Kodama of the East Tree trigger.
Resolve the Kodama of the East Tree trigger, choosing not to put anything from your hand onto the battlefield.
Resolve the Golgari Rot Farm trigger, returning it from the battlefield to your hand.
Resolve the Zendikar's Roil trigger, creating a token.
When the token enters the battlefield, Kodama triggers, putting Golgari Rot Farm from your hand onto the battlefield.
When Golgari Rot Farm enters the battlefield, it and Zendikar's Roil trigger.
Repeat from step 4.
This ingenious loop turns a simple land drop into an endless cascade of life and metal, fueled entirely by the overlapping triggers of your board state. When you play Golgari Rot Farm, its bounceland drawback immediately returns it to your hand, but Zendikar's Roil and Kodama of the East Tree turn that mechanical hiccup into pure momentum. Every time Zendikar's Roil creates an Elemental token from the landfall trigger, Kodama of the East Tree sees the new permanent enter and instantly leverages its triggered ability to redeploy the Golgari Rot Farm right back onto the battlefield, restarting the cycle.