Comet Queen was a member of the Legion Academy. She "Graduated" to the Legion of Substitute Heroes. A teenager from the planet Quaal-III, Grava was starstruck by the Legion and hoped to join by replicating the original powers of Star Boy. Taking her star-ship on an intercept course with the closest comet, Grava jumped through its tail naked and came out mutated with different powers than she had hoped for. This did not detour her and Grava bid her time, and built up some credits, to fly off to Earth and set out to prove herself worthy of Legion membership. She is able to fly at super-speeds while trailing a stream of stellar energy, much like a comet does. She has great skill in flying, showing hairline maneuvering through various obstacles at high speeds. She seems to be able to alter the chemical components of the gaseous trail she leaves behind - with various effects. Already demonstrated are effect include a gas which allows a deep, large cloud covering making it impossible to see through. Another induces drowsiness or even sleep in those who inhale its fumes. Whether she will demonstrate more remains to be seen.