Forest

Fangorn, Tree Shepherd

Treefolk you control have vigilance.
Whenever one or more Treefolk you control attack, add twice that much {G}.
You don't lose unspent green mana as steps and phases end.

Assemble the Entmoot

Creatures you control have reach.
Sacrifice Assemble the Entmoot: Create three tapped X/X green Treefolk creature tokens, where X is the amount of life you gained this turn. Put a reach counter on each of them.

Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.