Jungle - Full of trees, this is a rather peaceful stroll...Can spawn the T-Rex Boss.
Forests - Trees, but less vines, how wonderful. Can spawn Werewolf/Black Werewolf.
Ocean - Water, water everywhere! Can spawn the Megalodon and Tentacolon. Atlantis lurks in its depths.
Beach - Such fun it is to play in the sand with the palm trees. Found near water.
Deserts - Everything is so dusty, I do hope we reach water soon. No special mob or boss spawn.
Tundra - Let it snow, let it snow, let it...IS THAT A DRAGON?! Can spawn the Ice Dragon and Ice Elementals.
Sky Islands - High in the sky...Oh look, you can see the clouds below us now! Can spawn Ashkore, the Electric Dragon Boss.
Atlantis - Deep in the ocean of -400s, somethings seem to be teleporting around in there...I wonder what. Main inhabitant - Visitors.
Volcano - Is...is it active? No special boss or mob spawn, but a good place to collect lava. Found in Deserts.
Underworld(Hell) - It's so...dull and firey. Are those skeletons dancing?! Can spawn Dark BOSS and Dragon.