Calvin the Cat, referred to as this by Doofenshmirtz in Where's My Perry, also called Agent Kitty, is a golden brown tabby with brown stripes, paler chest/belly, and green eyes. His first name is unknown; not much is shown of him but he was seen in "Traffic Cam Caper"
Mindless animal mode
In mindless animal mode, Agent Kitty is sleeker and his eyes are bigger.
There is a confusion on its codename:
Most of the agents are named after the kind of animal they are, but when more than one animal would have the same code name, exceptions are made. The chicken in this episode is specifically addressed as "Agent C", which leads to the cat being referred to as a kitty. However two agents from different divisions can share the same name as Pinky and Perry the Platypus are both Agent P.
Also shown in the episode is a kangaroo, but it is not specifically addressed, so it is not known by what agent code letter the kangaroo goes by. Since these characters are not shown in episodes a lot they are addressed as Agent K.
An Agent W has been addressed by codename, but later, another Agent W addressed by codename appears ("She's the Mayor").
His secret file states that he's a ferocious fighter with razor-sharp claws and has natural stealth attacks. He's exceptionally clean as he bathes daily with a loofa-like tongue (but never with water). Also, he has a lovely singing voice. "(Where's My Perry?)"