This is an artifact found in the Uncharted Land, accessible via the portal if the creature has an appropriate token. Somewhere on this island, there is a cavern housing this object.
The World Egg manipulates the material plane's interaction with extraplanar entities.
Effect[]
While active, the World Egg causes conjuration[teleportation] spells, spell-like abilities, and effects to fail if the two following statements are true:
- The creature would teleport onto the Material Plane.
- The creature would gain the extraplanar subtype from being on the Material Plane.
Creatures summoned via spells with the [Calling] keyword are unaffected. While the World Egg is inactive, there is no effect on extraplanar entities.
Extraplanar Subtype:
This subtype is applied to any creature when it is on a plane other than its native plane. A creature that travels the planes can gain or lose this subtype as it goes from plane to plane. Monster entries assume that encounters with creatures take place on the Material Plane, and every creature whose native plane is not the Material Plane has the extraplanar subtype (but would not have it when on its home plane). Every extraplanar creature in this book has a home plane mentioned in its description. Creatures not labeled as extraplanar are natives of the Material Plane, and they gain the extraplanar subtype if they leave the Material Plane. No creature has the extraplanar subtype when it is on a transitive plane, such as the Astral Plane, the Ethereal Plane, or the Plane of Shadow.
Calling:
A calling spell transports a creature from another plane to the plane you are on. The spell grants the creature the one-time ability to return to its plane of origin, although the spell may limit the circumstances under which this is possible. Creatures who are called actually die when they are killed; they do not disappear and reform, as do those brought by a summoning spell (see below). The duration of a calling spell is instantaneous, which means that the called creature can't be dispelled.
Teleportation:
A teleportation spell transports one or more creatures or objects a great distance. The most powerful of these spells can cross planar boundaries. Unlike summoning spells, the transportation is (unless otherwise noted) one-way and not dispellable.
Teleportation is instantaneous travel through the Astral Plane. Anything that blocks astral travel also blocks teleportation.