@Thorvald: Those on back of it's head are ear cannals through which the creature is detecting sounds :D
Now, this ref was just for shape/look showcase and it will be quite usefull when modeling it. I have a plan to make a detailed reference sheet of Jištl since it's anatomy is... unusuall to say at at least.
It's skin is rough and hard, but it breather trough it. Just like Milk Worm (upcoming reference sheet as well) it detects it's suroundings via impulses, but unlike Milk Worms, Jištl's skin shouldn't be touched since it causes sensory overload to them.
Jištl also doesn't make any particular sounds but speaks human... and it is also the same size as an average human.
"I wish Worms had a fem-mod!"
*Monkey's Paw curls one digit.*
So are those the 'eyes' at the back of the head? That actually makes sense to scan above-and-behind given the general dimensions.