This is Mecha Sonic, from issue 39 of the comic book. I combined parts from 3 figures to create this one, Knuckles' body, Sonic's head, and Metal Sonic's arms and legs. Of course there was extensive sculpting needed on the head and limbs, which used polymer clay, but most of all I had to chop up Sonic's head quite a bit to match the shape. I removed the 4 spines on the sides of his head, then whittled one down to stick in between the 2 central spines. I've never chopped up a figure so much for the sake of a custom, but I did it because I always wanted this particular Sonic robot in my collection.