Just finished this guy the other night. I had to rebuild him from scratch, so I tweaked the design a little bit. The first one was made from WED clay, when I sealed it with shellac it didn't work very well and the sculpt cracked. I think crystal clear works better for sealing WED clay as I used it on the other two busts and they didn't crack.
He's sculpted from regular Super Sculpey, over a very basic wire armature. I boiled the Sculpey in a large pan to cure it instead of baking it as this method really produces a lot less cracks and the heat is more evenly distributed across the surface plus it cools down quicker in the water. The fin was made after I cured the Sculpey. It's made from milliput a two part epoxy that bonds very well with Sculpey and it's a lot tougher and is ideal for delicate details. Hope you like him and thanks for looking.