Limbo and Slaadi

Limbo is the plane of pure chaos. Slaadi inhabit the plane, gliding and jumping between the ever-changing chunks of matter that dot the plane. The Spawning Stone sits at the center of the plane, a relic of an ancient incursion by Mechanus. What was meant to create a modicum of rigidity to the plane instead began spawning the Slaad, embodiments of chaos, from the souls of the dead who strove for freedom above all else. The innate nature of the plane makes it nearly impossible for traversal by most.

Pandemonium

Pandemonium is the fourth level of the Underspire. It is a chaotic realm of howling winds and cavernous tunnels. The incessant gales drive most explorers mad. The Slaadi and Oozes that inhabit the plane are immune to this effect, however. Rikikikikit is the sole encampment of the level, built by half-insane explorers as protection from the level's perils. It is found deep underground and peopled by strange-mannered humanoids who have built up a resistance to the maddening gusts outside.