My avatar is a Trch'zon, a fictional animal in a world I design as a hobby. I'm acitve in a forum concerning this hobby where my avatar in turn has nothing to do with ficitonal worlds. So I make a little out of picking an avatar for every forum I'm in that has nothing to do with the topic of the forum.
Mine is just an old picture of me in the forest (forgot the place) with lots of giant and tall trees. This is also my facebook profile photo that I'm generally way too lazy to change it.