Ah, this one should be explained a bit. I drew it to represent the concept of the Ninja turtles (you know the ones) undergoing their initial transformation from standard beast to anthropomorphic crimefighter. as such I made it as mutate-ey as possible: the five digits on each hand and foot shifting, some growing, some shrinking, becoming the familiar 3 fingered, 2 toed shape folks are familiar with. The limbs stretching and filling with muscle, suiting a 2 legged creature. yeah, this one was a bit more of a chaotic transformation, so I thought a painful aspect would be more suitable. so yah.