This creature is a lovely creation from "Return to the Tomb of Horrors" and one of my personal favorites. It is a moving, sentient, sphere of annihilation just as the magic item. It mission, to consume and terroize high level characters.

   The living sphere of annihilation is a globe of absolute blackness, a ball of nothingness 2' in diameter. A sphere is actually a hole in the continuity of the multiverse, a void. Any matter that comes in contact with a sphere is instantly sucked into the void, gone, utterly destroyed-- even wishes and similar Magikcs have no effect!

The way to kill it: Should a gate spell be cast upon a sphere, there is a 50% chance that the spell will destroy it, 35% that the spell will do nothing, and 15% that a gap will be torn in the spatial fabric, and everything in a 180' radius will be catapulted into another plane or universe. If a rod of cancellation touches a sphere, a tremendous explosion will occur as they negate each other. Everything within a 60' radius will sustain 3d4 x 10 points of damage.

This creature is copyrighted under Wizards of the Coast