A creepy character you created there, I've never seen "Mack the knife" portrayed that way. Could be a very promising start for a graphic novel or a 3D-Animation about a serial killer - or is Mack just seeking revenge for his lost arm? For a crime that was done against him? Is this man he watches in the dark ally a complete stranger to him or someone who deserves his hate?

Anyway, it looks good so far for a start, hope this will continue some day.