Kay is a human woman of Hispanic background, with tan skin and dark hair. A former combat medic, she uses her martial and medical skills to keep everyone alive. Sometimes she gets turned into a cat, or is a cat in alternate dimensions. Alter!Kay typically has medium-brown fur with dark points, often Tonkinese. Full-size images are in the Alter Kay gallery of my LJ scrapbook.
This was the first "kitty with gun" image I found, before I settled on a usual appearance for alter!Kay. I still think it suits her.