The Abyssal Hang-Tooth is an exotic Dracolisk which can be used as a mount in Dragon Age: Inquisition.
Acquisition
After completing the war table operation The Hunter Shade Dracolisk in Orlais, and capturing Caer Bronach in Crestwood, the mount can be purchased from the mounts merchant in Skyhold for 385 
.
Location
Once acquired, it can be found in the stables in Skyhold.
Gallery
Abyssal Hang-Tooth mount