Someone who is totally and utterly obsessed with Katy Perry and can't do anything without it reminding them of Katy Perry.
Person 1: Omg how pretty is that love heart?
Person 2: OMFG..Katy Perry had a Love heart behind her when she was performing at Radio1's Live Lounge..and When she was singing POM which is Part Of Me it had a crack through the middle..
Person 1: Jeez man, tell us your life story!
Person 2: Its called being a Katycat and having Katy Perry Disease!