Create easily 2D high quality animations with layers for filters etc, using Synfig Studio
Synfig Studio is a free and powerful program that will let you make great 2D animations faster, without editing each and every frame.
The program features editing in layers to apply filters, gradients, distortions, fractals, etc. A Skeleton Distortion layer can produce exactly the effect that you need. As you would expect, Synfig Studio’s toolbox supports scaling and rotating, drawing, color fill, etc. The GUI features tabs for working with several projects.
You need some time to learn how to find your way in the program’s interface and functions, and you may miss some tools offered by even more advanced programs.
If you are after 2D animation this is definitely an application you should try. Note that Synfig Studio includes detailed documentation and examples.