Here's the two axis joint for the triceratops head. Fixed to the body this will allow the triceratops head to nod up and down…

…and move side to side. I've added the egg shaped piece of these stop motion animations to make the movement clearer, it won't be part of the final design.

The finished joint fits inside the head like this with the end where my fingers are connected to the body.

Next step: I'll be putting together a body and tail. At the moment my plan is to have the tail fixed, and the legs made from flats of double thickness card attached through circular holes on the body side.