It's very fashion-forward to put remnants of dead creatures in your hair... so I am told. 3D printing makes fashion possible without murder of innocent creatures.
I used the bone from this thing https://www.thingiverse.com/thing:367268/files and scaled accordingly.
skull_hair_tie_2.stl | 22.6MB | |
skull_hair_tie_2_bone_only.stl | 210.3KB | |
skull_hair_tie_2_skull_only.stl | 22.4MB |