Requires

Steps

1. Play Petrified Field.
2. When Petrified Field enters the battlefield, Kodama of the East Tree and each Scute Swarm you control trigger.
3. Resolve the Kodama of the East Tree trigger, putting nothing onto the battlefield.
4. Holding priority, activate Petrified Field's second ability by tapping and sacrificing it, returning Echoing Deeps from your graveyard to your hand.
5. Resolve the first Scute Swarm trigger, either creating a 1/1 Insect creature token or a token copy of Scute Swarm.
6. When the creature token enters the battlefield, Kodama of the East Tree triggers, putting Echoing Deeps from your hand onto the battlefield untapped due to Archelos as a copy of Petrified Field.
7. When Echoing Deeps enters the battlefield, each Scute Swarm you control trigger.
8. Holding priority, activate Echoing Deeps using Petrified Field's second ability by tapping and sacrificing it, returning Petrified Field from your graveyard to your hand.
9. Resolve the first Scute Swarm trigger, either creating a 1/1 Insect creature token or a token copy of Scute Swarm.
10. When the creature token enters the battlefield, Kodama of the East Tree triggers, putting Petrified Field from your hand onto the battlefield.
11. When Petrified Field enters the battlefield, each Scute Swarm you control trigger.
12. Repeat from step 4.

Results