I got the link from splitbrain.org, however I was hesitant to post the image, since the site didn’t display any information about the conditions of using it:
However I finally got a response from the cpbgroup (the creators of the Hero Factory), in which they state that I can use the image on my personal website as long as I include a link back to them. Not the response I was hoping for, but at least they have got back to me. It is very important to license your work and think ahead of time how you would and wouldn’t like your work being used (an other shortcoming of the reply was that it applies specifically to me and my blog. While I assume that they would license it to everyone under the same conditions, it would have been nice if they stated this in their response).