Here's the part of my muzzle in it's current state. This was first carved from a block of dense foam. Then I cut through to separate the upper and lower parts and started coating it with rubber. When it's done it will be much smoother and colored appropriately. Also the rubber will transition to Ultrasuede which will transition to fur.

When it's done I'll show how the corners of the mouth work. They are foam which was carved and applied and will be further carved and coated with rubber. The inner workings (the forms of the hollow insides of the parts) are actually pretty complex.

This is posted to show the basic idea of the human-ish donkey lips to some commissioned artists. The form of the lips will be further refined but the idea is evident. Part of each nostril is still to acute but I'll correct that too.

...more suit-part images once my house is more under control. I'll take some pics of the back of this where the nostril tubes connect, and of the connection hardware for the rest of the muzzle, teeth and gums, and tongue.