Thanks guys!

Mindset, I gave the tongue a procedural noise texture in the bump map channel, with a fairly high bump value. The scene was rendered using Keyshot for ZBrush.

Marco, many thanks for the links. That's quite some interesting stuff. I don't do a lot of animation, especially not character animation, because it's quite elaborate work, with all the rigging and the keyframe jungle that results from moving all kinds of body parts. But I'm definitely interested in the subject matter.

Do you know Mixamo ( https://www.mixamo.com ) ? It seems like a very interesting facility for easy character rigging and animation.