As an avid roleplayer, I have had (seriously) more online names than I can count. "Furry" names alone total somewhere in the 50-100 range (closer to 150, likely, if one counts all of the characters I put in my stories), and some of the names I used several times for distinctly different characters!
Obviously it'd be way too spammy for me to go into detail on all of them, but I wanted to give some quickies on a few, I would be happy to go into more detail if anyone is very bored and curious. ;p
Chibiabos - He's become my main OOC furry fursona. He's a wolf (duh! if you couldn't tell from my avatar) taken from Algonquin legend (Algonquin is a family of Native American tribes all over the Great Plains extending far to the present-day southeastern U.S.) for whom Chibiabos was a wolf who had drowned in a lake and rose to become lord of the spirit realm. I first used the name on Thunder Trails MUSH as my admin character (which is why I wanted a god name ;p).
Ironhoof - I wanted a simple descriptor. What part of her did I want most well-known? Her hooves. What did I want them known for? Strength and resolve. I could have come up with "Granitehoof" or "Diamondhoof" or somesuch, I suppose ... I just thought "Ironhoof" had a nice, rusty ring to it. ;p
Klondike - I briefly looked after a sweet wolf/malamute mix named Yukon and for the few short weeks he and I were together, he never ceased to amaze me with the tremendous amounts of love in his heart despite a bad situation he and I were in together. I started using the name Klondike in honor of him. Klondike has actually been several characters for me, all wolves but each with distinctive character backgrounds, personalities, etc.
Fortivirago - I took a couple latin words and mangled them together. I forget what words they were exactly, I think they were "strong" and "warrior."