Tarterian dragon

Tarterian dragons were strong-willed planar dragons native to the prison plane of Carceri. They acted as both wardens and prisoners of the plane.

Description
Tarterian dragons were emaciated with drooping flesh and tattered wings. Their leathery scales were colored in gray, olive green and black patterns, and their black eyes glowed with green light. Their fangs and claws were black as well. They seemed to wear a permanently grinning expression.

Although they could get their sustenance from any source of food, tarterian dragons enjoyed eating fiends and condemned souls the most. They preyed on any creature perceived to be weaker than them.

Combat
The typical battle tactic of tarterian dragons was to separate and constrain their opponents so they could face them separately. To that end, they made frequent use of their two breath weapons: a line of force and a cone of gas that sapped the will of its targets as if hit by a crushing despair spell. They could also cause effects similar to the forcecage, imprisonment, maze, and Otiluke's resilient sphere spells.

Extremely mobile creatures, tarterian dragons were also immune to effects aimed at restricting their movement, such as hold monster, solid fog, slow, web, and other paralyzing effects. They were highly resistant to force energy.

Society
In their home plane of Carceri, tarterian dragons thrived on a variety of environments and across several layers, ranging from the jungles of Cathrys to the mountains of Colothys.

In addition to their native plane, tarterian dragons could also be found in the Dismal Caverns and the Dragon Eyrie, but were very rarely, if ever, found on Toril. They could be found alone or in families as they raised their young. Clutches of young tarterian dragons were also commonly found.