This is a Horse fidget Spinner I designed. It is designed to be on the smaller side so it should fit in kids hands, but adults can play with it too!
This requires 608ZZ bearings.
The bearing covers also have a small lip to prevent the covers from accidentally touching the bearing and slowing it down. You can squeeze these covers firmly without deforming them and slowing the bearings.
Use my Spinner Press to help insert the bearings. http://www.thingiverse.com/thing:2275122
The hair of the horses require really good bed adhesion or they will tend to curl a bit. It's not catastrophic but your print won't come out perfect. I recommend blue painters tape and wipe it quickly with isopropyl alcohol.
I like to print PLA at 205c with a bed temp of 70c.