The Watcher of the Mists
This creature appears to be mostly humanoid, but with back-bent doglike knees, three-fingered talons for hands, and a tiny set of hands that grow out of the sides of its mouth, which is filled with rows of sharklike teeth.
According to notes found among Nualia’s belongings, these creatures were created by the ancient Thassilonian wizards as spies and shock troops. They are created using a magical artifact called a Runewell, but, once created, are also capable of breeding.
Sinspawn encountered so far appear to be proficient with weapons and armor. They are also quite capable of fighting with tooth and claw. They appear to speak in a harsh language that no one has been able to translate without the use of magic.