a male cat is called a "tom" or "tomcat

I knew there'd be an explanation somewhere! :) http://www.etymonline.com/index.php?term=tomcat Some names are common enough to have general uses uses (eg. average Joe, every Tom Dick and Harry) or even non-human uses (jacknife, to jack up a car, and so on). There's usually a story behind the use.

It is just a name. My friend's cat was named Fred.