This is a bobble-head Brain toy that is based on an actual MRI brain scan, so it's “MADE WITH REAL BRAINS”. 

This toy uses a 3D printed base and spring and has a recess in the base that will hold a 10mm magnet.

The brain requires supports, but needs little to no infill (10% is fine).

Tools to install both the long and short springs are included here, tool use is recommended, but not required.

This is based on two prints.  First, the MRI brain scan model by Jan Vejtasa (https://www.printables.com/model/230891-human-brain/comments).

The second print is from the bobble head prints designed by 3d-printy (https://www.thingiverse.com/thing:5409630) that supplied the original base and spring mechanism designs.

Enjoy!