Don't know if you are the do it yourself type, but this is a free program that would allow you to make and edit your avatar.
Photoscape - Download Just right click your avatar and save it to your computer. After downloading program open your avatar with program and add a new picture. You can also edit a picture with this program. There is also a test forum with several threads offering to make you an Avatar. Here's one such thread:
http://www.yorkietalk.com/forums/tes...vatars-40.html