So here's some thoughts on this.
At the start I didn't really change much.
Put the tile ref on a separate layer.
Changed some settings to get it ready in GG.
Added a couple frames of his mouth wide open for some hang time before his jaws close.
Roughed in the biting frame.
Put in frames to show the impact of the bite.
Just a couple simple resolve frames.
Also intentionally stretched out his face some to add some more action to the bite.
Threw in a small particle but removed later so I could focus on working with the flower.
Tweaked the first blur some.
Added in the black of his mouth and teeth which are easy to visually follow.
Anything that reads as multiples well, teeth, eyes, etc is good for a blur frame.
Made his mouth open just a little bit wider each frame when his mouth is wide open so that there is motion and change.
Changed the bite frame some to include the color of the teeth.
Put a little more bounce in the bite impact.
Worked on the stalk some.
Tried playing with a rubber band effect when he stretches.
It drew some attention away from the bite so I took it out, but interesting to try.
Enlarged the teeth just before he bites down.
Made the stalk simpler, added a small wave to taunt as he stretches.
Decided to take out the bounce before he pulls back to simplify the overall motion.
Added a couple of stretched frames to lead into the blur on the pull back.
Change the shape a bit of the pull back blur and drew in teeth.
These 3 are pretty much the same, just played with some particles and without.
The faster the animation plays, less delays, the more range of min and max speed you have to play with.
On the left is the same animation as above at 5 delays.
On the right I've dropped it to 4 delays and added more speed contrast to different parts of the animation.
There are parts of this I have probly not explained that well.
Check out the pixels and ask questions if you need some clarity.