Hey there!
I did yesterday one those free animation courses that Crehana is offering for free during 24h
https://www.crehana.com/curso-gratis-del-dia/
While I didn't finished it because it was too long I did do this little animation practice which I found super fun :3.
Technical Info:
Animation done frame by frame
using Adobe Photoshop CC 2015
it has 27 frames each during 0.1 sec
Final Art

Click to see in full size

