alrights, so heres my 2 cents
since ya want some crits
(looks good by the way)
lets start with the sprite itself, disregarding the animation for the time being...
heres a quick edit i made that might help to illustrate what im talking about better:
mine ----- yours
first i got rid of the extreme yellow highlights. i found them to be very distracting and not suiting the material it was on. stems and flowers are delicate.. they do not have extreme contrasts. so i took your next lightest shade for green to replace your yellows on the stem. created a new colour for the flower.
then i looked at your outlines. if this is a sprite then generally you have the outline as a dark colour (opposed to colouring into the lines) to allow your sprite to be put onto whatever background it is placed. for things like this, i like to look at it as inner and outer lines. your outer lines are the ones that are just on the perimeter of the object, while inner lines are details within. The outer line should be the darkest and only used in the sprite in the darkest of places. The inner lines defines the details inside and helps to AA the outer line. I did this for the stem and flower.
next i found that there was no real defined lightsource... so i put it as top left corner.. because of the ambient green you used on teh side of the face. then i reliazed that the eye can easily be missed, which shouldnt happen (in my opinion) because the eye can give alot of the expression and emotion. So i darkened under it and threw in a brow to help emphasize it more giving more personality to your plant.
i played with colours a bit.. dropped some contrast to make it more delicate and just played around abit. on the stem.. lighter colours are more washed out then the darker ones, similar to a real plant.
i tried to keep the vibrant colours without alot of contrast to help give a more natural feel.
i find your sprite very distracting with the yellow highlights and undefined lightsource. some of the lines such as on the outer parts could be darker, and you need to define the different sections more especially the lip right around the eye.
thats roughly about it.. hope my edit made a bit of sense.
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now onto animation.
personally.. i feel that there is too much going on at once. when the stem zigzags, leafs expand and the mouth blurs i find to be way too much happening that you become overwhelmed and you arnt able to blatently see what is happening. especially the section where the head blurs between being closed and chomping i feel is too 'blurred'.. opposed to a progression with the blur i instead see 3 main key frames. closed, mid blur, and chomp. the blur should be the transition frames between closed and chomp. im order to do that, since it is such an exageration perhaps throw in another frame. it all happens to quickly and just as you realize whats going on its over.
mmm the steam and leafs seem alright. however.. the only section that bothers me a bit is when the stem zigzags. it seems to zig when the motion blur is happening. yes i understand that you want to show the force and jerk movement/decision that happened.. but since he is reaching out like that the stem should tighten and narrow. like pulling on an elastic band. at a relaxed state it is larger and more mobile. but when stretched out like when the head is chopping the stem should narrow out and become more straight/stiff. give it more of an elastic feel like the plant is reaching out as far as it possibly can before it reaches its limit opposed to an explosive energy. this might help to tone down the commotion aswell.
again lightsource.. keep it consistent, and try not to run the highlight lines up and down, backand forth like that on the stem. from what i know.. highlights shouldnt move too much because the lightsource doesnt. its the shadows that move, and highlights remain mostly in the same spot - i believe.
the final chomp i feel should be held longer. with that much force put into it he shouldnt be able to recouperate so fast. give a small pause there, to show the true impact that the plant was intending. here it looks like he builds up all this force, all this power but decides to pull out just at the last second. he does not follow through with the bite. even by watching it the key frames seem to be the motion blur and then halfway into the pull back. the chomp itself seems to be a transition frame, when really it should be a major key frame since that is the whole point to the effort put in by the plant. i barely see when his mouth first closes, when that should be prominent. also, throw in a clenched jaw at the chomp.. show some cheek bones.
the leafs on the head all seem to change size. getting larger. the leaf on the side of head (our right) seems to jump up aswell. theres probably too much movement on the head leafs too. the ones on the stem are fine because they could be considered arms or hands, that wind up for the chomp. but the ones on the head should be thought of more as hair. as the head moves backward, they shoudl sway front alittle. as the head shoots forward, they should almost be flat against the head. right now they seem to be doing their own thing without much sense behind it... no forces causing them to do that.. doesnt make sense for them to relate to a limb.. probably adds to the clutter.
right before the plant goes in for the chomp, perhaps pull it up higher, make it seem like its drawing up to its full height kinda puffing out its chest almost -- making itself look big and intimidating. perfect time would be when it is facing straight front probably.
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hmmm, so thats about all that i can see right now. but its late.
perhaps ill take a better look at it tomorow and see if i can add anything else.
hope this helps, and hope that i made sense with what i was saying
very soild animation.