Shadowclaw is the brother of Darkmask and a "member on probation" of H.A.L.O.
Shadowclaw began as Darkmask's brother Ralphie, though when he first appeared the family resemblance was not apparent. He was a cat in the service of Dr. Hood (and was, at that time, called "Ubercat") who had a grudge against life in general. It is not until after the recreation of the HALO universe that it is revealed Ralphie was indeed born a raccoon, and that the change in his appearance is due to his power. Ralphie made an effort to aid J Shifter in defeating Hood at the very end, but he was torn apart by the fount of creation in the Microverse. Once reborn, he decided to turn over a new leaf, but he adopted his new codename after he had come to terms with the nature of his power.
Ralph has a very angry personality. This is, no doubt, due to his ironic situation. As a child, Ralph was forced to compete with alley cats for food and space, and came to hate cats. Now his power has caused him to become a cat with no way to turn back into his true form. Ralph hates his body, his powers and himself.
Since being reformed, Shadowclaw has become a much more quiet, reserved, quiescent individual, though he is still very bitter.
Shadowclaw is a polymorph, but he is limited to variations on the feline form, which may include extinct and as-yet-undiscovered species as well as familiar ones. His choice of form is determined strictly by the needs of his current situation. He is also a fierce fighter, and is very difficult to contain when he goes berserk.