Like all Talokite, he has blue skin and pointed ears and was adapted to the harsh desert terrain of her planet.
Grev lived with his grandfather Sarven Mallor, the Planetary Champion of Talok VIII. His father had died in a cave on the outskirts of Talok City. His grandfather's work kept him in the city, but Grev preferred to remain with the rest of his family near the site of an ancient cave, sacred to their ancestors.
When worshippers of the god Makkas the hill dwelling Yakka-Mahor encircled the enlightened city where most Talokites live, the citizens had no way of defending the city. They people searched the city to find the descendant of the the last Shadow Champion and they found Tasmia Mallor. Using a compass that was supposed to point to the shadow cave, where she found her cousin Grev. The two scared children entered the cave, where they were enveloped by the shadows, and empowered with the hereditary ability of their ancestors. Tasmia became Shadow Lad with his cousin and they drove the Yakka-Mahor back using their powers to manipulate the shadows and darkness.
- Talokite Physiology: As a non-terrestrial being, a Talokite's body chemistry is different from that of a normal human, providing them with different physical attributes, such as the ability to exist in the vacuum of space longer than a normal human.
- Darkness Manipulation: Shadow Kid has the ability to create and manipulate darkness.
- In Superboy and the Legion of Super-Heroes #240 he was named Shadow Lad.
- 18 Appearances of Grev Mallor (Pre-Zero Hour)
- 2 Images featuring Grev Mallor (Pre-Zero Hour)
- Quotations by or about Grev Mallor (Pre-Zero Hour)
- Character Gallery: Grev Mallor (Pre-Zero Hour)
Legion of Super-Heroes member