Springheart Nantuko for its bestow cost by paying ({1} magic symbol) ({G} magic symbol) , attaching it to the animated Forest.
Play a land. When the land enters,
Springheart Nantuko triggers, causing you to pay ({1} magic symbol) ({G} magic symbol) to create three token copies of the Forest that enters untapped.
When the Forest tokens enter,
Springheart Nantuko triggers three times.
Holding priority, activate two Forest tokens by tapping them, adding ({G} magic symbol) ({G} magic symbol) .
Resolve the first and second
Springheart Nantuko triggers, choosing not to pay and creating six 1/1 Insect creature tokens.
Resolve the third
Springheart Nantuko trigger, causing you to pay ({1} magic symbol) ({G} magic symbol) to create three token copies of the Forest that enters untapped.