Here's my first try at building a wolf puppet head with a flexible 3D-printed head base - printed with TPU filament:



I adjusted my base plate for the eyes to fit exactly inside the head and attached it with cable ties. The plate was printed with PLA filament (it's rigid and makes sure that the top part of the head cannot deform too much). 



The Bowden cables that are connected to the eyelids are self-built - I used a 0.8mm diameter braided stainless steel cable in a PTFE tube with a 1mm inner diameter. There's a black Shrink tube around the end of the PTFE tube - that adds a surface that can be glued to the head (gluing PTFE tubing does not work).
For padding inside the head (and for the most flexible parts of the body) I used a 3d mesh made of Nylon (that's sold as a mattress topper).

https://www.youtube.com/shorts/UKsNhnFJ8EM

The legs have now a joint that is a hybrid between a swivel joint and a ball joint. That means the puppet can do the splits - and I also made the legs easily removable in seconds.

The ears, nose, teeth, tongue, the half-ball joint for the legs, and the pin that holds the legs on the body are also printed with flexible TPU filament - that makes them very tough - like rubber.