Forest

Forest comes right after Plains, and is in fact right next to Plains.

Overview
Since this is a forest, some levels have trees in the way. Trees help block off your enemies, but don't have infinite health.

Gained Allies
Stick-pult (2-1)

Wooden Fence (2-2)

Poison-shroom (2-3)

Bush (2-5)

Torchwood (2-6)

Sapling (2-7)

Wood-pult (2-8)

Lily Pad (2-10)

Encountered Enemies
Creeper (2-1)

Killer Rabbit (2-4)

Zombie Villager (2-6)

Bat (2-10)

The rest are in debate.