I remember this lame fatality in MK4 where he turns himself in an actual scorpion and rips off the upper body of the opponent... The aha-erlebnis of it all!
Anyway, neat idea for using scorpion-like plates as armor. Could be cool.
I would push the silhouette a bit more though, give the man some pincers!
Nice touch on the scorpion stinger on the end of the spear as well.