Here's Skullkid, illustrated by the amazing Michael Fleming

And here's some highlights of the working session in After Effects.
It took me quite some time to figure out how to do a proper run cycle as I rarely happen to do any.
The most fun part was probably adding the deformation that makes the head bend one way and another, at each step, it's so easy to do, while it gives a lot of depth to the animation.

And also, a small edited version I used as a Xmas wishes card.