Hi,
2 years ago I discovered Spriter. Since then I did tons of animations and one of my favorites are the animations of my skeleton game assets.
When you use Spriter the right way you can create animations like this
Not all skeleton characters shown here but there are plenty more of them..
The whole package is available here: Graphicsriver
here GameDev Market
and here Itch.io
or even here Scirra Store
I have even updated the package to version 1.1 and added a run animation + w