Having been playing Eve for a couple years now, and having at least a marginal interest in things mercenary and null . . enary, I've heard a number of mentionings of different "cats", and, I thought exactly what the title says. With a little bit of random clickery, I managed to get a little more info on it. So, just give me a second to adjust my ass in ye olde rocking chair, and I might be able to elucidate on that, or at least tell you about it, a little, maybe . . .
To start, we need to set the way back machine to Feb 2007. A female player started in Eve as a fairly hard core indy player doing market trading, mining, manufacturing, etc. After getting ganked by pirates in lowsec, she met another player (who had tried to save her during said gank) who soon turned pirate himself. After being regaled by his tales of piracy hijinks in lowsec, she decided that it t'was to be the yarrrr life for her too. Her current toon was not suited for such a direction, so she created a new toon, on a new account, and called her . . . wait for it . . . NANCY! No, just kidding, it was actually the birth of Mynxee.
So, fuckin' YAWN already! HELLCATS?!?!? Yeah, so apparently, at some point, the Hellcats had a battleship doctrine that used Abaddons. As small gang pvpers, using mostly frigates and cruiser class ships (from what I've been able to see) that bit about Abaddons might be a little sketchy. At any rate, apparently, in late 2010, Pandemic Legion, in a pique of homage to the all-female corp and also to the TV show, started naming fleet ship doctrines with the suffix of "cat". Hellcats, Thundercats, Slowcats, Herocats (definitions of the last two cats differs), and yes, even, supposedly LOLcats, again, details of the last one are murky, and NO, it's not a picture of a cat with guns taped to its paws or something . . . I think.
What I want to do, and possibly should have done, was maybe send Seleene a quick message and see if he knows about the origins of the whole "cat" meme. Perhaps I shall, and get back with a quick edit when I get an answer. :)