Quite a long time ago, I started to play Quake over LAN with some of my friends, making it necessary to find a nick. At first I had nicks like Metalizer, Harvester_of_Souls, Reaper_Man etc. (See a pattern there?)
I didn't like any of them much, so I had a new nick about every two weeks.
One day I woke up and had the word "Isegrim" in my mind... (Happens quite often with me: I wake up and have the solution to a problem I haven't thought about for some time... Anyone else share this phenomenon?)
Anyway, some time after I discovered the band "Finntroll", and on one of the bandshirts there is a troll depicted that looks quite like me...
I found that I sometimes DO feel like a troll and that Isegrim is a rather nifty name for a troll.
And so it stuck...
(Btw. Isegrim is the name of the wolf in german fables...)