"Grayson" is an artifact costume in the StrikeForce Kitty series, based on Nightwing from the Batman franchise.
Dick Grayson was the original Robin and Nightwing in the comics.
StrikeForce Kitty 2
"Grayson" adds 15 strength, 2 health, and 11 speed to that kitten, for a total of 29 strength, 20 health, and 25 speed, from "Warbler".
StrikeForce Kitty: Last Stand
"Grayson" is a costume that can be obtained from defeated raccoons in StrikeForce Kitty: Last Stand, look on pages in the "Melee" category.