I just discovered the Thorkul's bite, and I have only 3 informations about it:
_ it instantly kills the player if successful
_Thorkuls seems to go into it's hole before doing it
_ it gives 5% necrostasy
I do not know how to add a skill, though, so I did not wrote it in a correct place.
Also, with the draw of the missiles, I thought that it have ice based damages, but it seems I'm wrong, since wearing Aysor's amulet does not changes damages.