Nagur

The Nagur are not a servitor race per-say, rather they are members of the demonic race who hold five or less links which is not enough links to start a household. They remain eternally under the house they were born to, unless they marry into or are hired by another house. Very few try to make their way as Freemen within the realm by taking up trades or performing specialized skills. Most Nagur find places working for the prince or one of the greater houses if their own house can not support them. 

They have the ability to shape shift, can use demonic magic, and share the immortality the Greater Demons do. The vast majority of the demon realm is made up by Nagur.