This prompted me to checkout Fedde's Flickr stream where I found these albums dedicated to custom 'characters'. While not all of them would qualify as minifigures, the fig is featured in many ways. My favorite was this custom mer-man warrior combining elements of Harry Potter, Castle, and Atlantis. A cool little stand to boot. Based on what I've seen, don't be surprised if Karf Oohlu makes the occasional appearance here.
(Picture from Karf Oohlu's Flickr stream)