What is not visible in the preview animation is how detail the mouth made. Initially, I did a very anatomically accurate model of the jaws, using photo of wolf skull as reference. But it does not fit in to not very anatomically accurate wolf head so I had to slightly change the proportions.
And then I started making material and a that's where the real trouble began. I could not understand how the inner mouth skin reflects light. Who knows how many photos of yawning dog, I saw trying to understand this, but then it hit me mouth covered with moisture which has its own unique characteristics to reflect light, so it should be not one but two glossy filtors.
Yes, and it also now has a normal map.