I was commissioned to originally assist in designing a character. I was later commissioned to create the suit.
The mask is built on a plastic mesh base with upolstery foam and covered in fur. There is EL wire running in the mouth and horns that operate on a switch/battery. The mouth opens when the wearer opens their mouth. The claws are black sculpey. The horns are soft and squishy so they don't damage easily.
The result was very well liked and comfortable to wear. It was completed just in time for a convetion.