Other Areas: Darkened Town, Bat Island, Underground City, Pyramid of the Dreads, Necroshpere, Dark Tower, and more.
Monsters: Dread Bat, Dread Bear, and more.
How to get there: Merle Ambrose is going to send you to NecroHaven after you finish all the worlds. Merle Ambrose is going to tell you to investigate the Undead's return, and how the undead is going to rule that world, since they failed at the other worlds.