There are two people that does great work with fusing people. Their names are DoodleDowd and JHcolley. Both these people do great work in fusing (or fuzing in their words) whether it be actual people or slime hybrids. They even took up two seperate groups that they pertake in that involves merging as well. Those groups are Morpher Academy (which is decommissioned yet still operational) and Morpher Manor. I got to say, all this artwork is top notch. If you want, you can check it out. Here are the websites.
DoddleDowd:
http://doodledowd.deviantart.com/
JHcolley:
http://jhcolley.deviantart.com/
Morpher Academy:
http://morpheracademy.deviantart.com/
Morpher Manor:
http://morphermanor.deviantart.com/