The jumpiness only comes in when the whole thing loops and it's the hardest to make two ends of any sort of cycle come together smoothly. Other than that, it's really good. Not only did you make the fucking head turn, but also colored it and put in shadows and highlights and whatever the fucks and made it all nice and fuck... you little shit. Anyway, nice job. I really hope you have a new idea for some sort of animation and have the will and energy and time to make it, because we need more people capable of doing that on ng here. Seriously, we do. Seeing what you've done so far is pretty inspiring, at least to me, and I'm looking forward to seeing more.
I feel like if you re-drew the frame when the thing "jumps" it would look much smoother or added another inbetween, or both or whatever, because this is really nice. You're most likely doing something better than fixing this anyway, so whatever, just wanted to give some input I guess :P