Hollow heads for wireless LEDs for example.

DECALSI added a .png with the water transfer decals that I made using a regular inkjet printer and white water transfer foil. If you want to use them make some test prints to scale them accordingly. Don't forget to mirror them before printing onto the foil!

3D PRINTING SETTINGSPrinting with tough resin is recommended (I tested generic resin but elbows on the lower arms snapped when I clicked them in... not hard to repair even after painting but rather annoying). Make sure to wash the joint cavities properly as any leftover resin will block movement especially at the hip.

FDM printing might work for you but will require experience with custom supports and part orientation for good results (tolerances may vary depending on your extrusion settings).