Make the shape that you want in plasticine / plastaline then laminate it with strips of paper and glue (the more strips you layer then the stronger the base cast will be.  This can then be cut off the plastacine mould and stuck back together again.  You need to make sure that it is completely dry before cutting off, try to avoid pva as this is plastic and prevents the inner layers from drying properly.

When you have stuck the cast back together again you can build up the detailing using the fine mache recipe (Peter Favereaus tutorial) rip the tissue up and soak in water, then blend with a hand blender before squeezing out as much water as you possibly can.  Get the paper as dry as possible before adding the glue to make your pulp then sculpt away.  Once this is dry you will be able to sand back the rough surfaces before adding gesso and paint.

I use this method to make the heads and torso's of my puppets and find it is fantastically quick and lets me make quite complicated base shapes.

I love the Aslan head, can't wait to see what you do with Fenris

I suspect you would find that a hanging nosepiece would flop with movement unless you adhered it to the wearer's face somehow (surgical adhesive?).

I saw a mask about 40 years ago in a local parade that was composed of a wire frame with muzzle/teeth, eyebrow ridges and ears that appeared to be made of papier mache pieces (made indivicually, I'm sure) attached to the frame. The frame was almost skeletal in appearance, and probably made from common household wire.

Thank you for reminding me of this!

Your Aslan is beautiful!

Sue