Dimension Zero is a reality of low gravity where their inhabitans had grow to gigantic size. They can observe the standard reality through lighscopes and from time to time visit using special belt to help them to endure the universe standar gravity.

Dimension Zero was discovered by Green Arrow and Speedy when the barriers between realities were weakened by a comet, allowing objects from one dimension to pass the other and causing to Green Arrow and Speedy being temporally trapped in that dimension, until Xeen Arrow, a local superheroe helped them to return home.

Dimension Zero is under the Guardians of the Universe jurisdiction, and count with a representative inside their world, the Xeen Lantern.