official or user created. if it is user created, follow these instructions:
you could do one of two things:
1st:
click on your name (prof. xavier)
up at the tope of where your avatar is, click on Avatar Options.
you can pick one from the admin gallery
2nd:
repeat steps 1 and two
go to google or any other search engine that finds images
put in what you want, click search, and when you find the perfect pic, click on it.
at the top, click on the image (i suggest using google as that is where my instructions are leaning towards) and the image will come up as a full size. remember, the image must be no larger than 75 x 75 pixels
click on the address you are currently in: it will highlight
right click and select copy
go back to your personal info and where it says Enter a URL to an online avatar image press ctrl>v (the letter v)
hope this helps