I found this about 2 years ago, loved it as soon as I saw it and saved it,only thing is that I could never remember who made it. This is absolutely awesome Zaaz, I love the way Bulbasaur's vines come out, it makes me happy to have inspired you. If you still have the piv. file I would really appreciate if you could share it with me, I could possibly even continue it.
That animation looks really smooth and I dig everything that is smooth... everything ! You could move his back and head to show some recoil as Zaaz said and maybe you could make him looks less stiff by moving more joints in each frame, not like just to move them but to actually make the animation look better by adding more movements and making it more realistic.