Here's an edit:
I tried to apply some of the "principles of animation" as I remember reading them in some guides.
A bouncing ball is a classic animation exercise.
See how the deformation follows movement with a slight lag. It's not realistic for a solid pumpkin, but 'feels right'
I gave a more parabolic move by letting all three images "at top" have the same height (well, almost).
I also remember that the last falling frame before getting contact with the ground is visually very important, don't hesitate to exagerate the deformation as if the pumpkin was anxious to bump into the ground.
My edit still has a problem of noise/instability in the right and left edges (as if the borders vibrated), it would require further fixes.