Wizzy's 3D printed parts can be printed without support, minimal infill, and ~3 shells. Before we dig-in, I've broken the 3D Printed Animatronic Tail out into a separate guide.
Build that first...
Tinkercad: 3D Printed Animatronic Tail
Our head mount is simple: head plate, flanges, and a frame for a standard-size servo. Again, no support, minimal infill, and ~3 shells should be plenty strong.
Tinkercad: Wizzy the Cat Head Mount
The bottom (body) flange is for the 21 mm dowel and the top (neck) is for the 12 mm dowel