Yeth hounds are evil outsiders that delight in hunting intelligent prey. They lope through the night skies, relentlessly pursuing their chosen quarry for miles, and harrying them with their frightful baying. Yeth hounds hunt only at night. They fear the sun and never venture out in daylight, even if their lives depend on it. A yeth hound stands 4 feet tall at the shoulder and weighs about 400 pounds.

Yeth hounds do not collect treasure, having no use for such baubles. The thrill of the hunt and the sweet tang of fear in their prey is all they value. However, some items of worth may occasionally be found in a yeth hound den, the discarded remnants of prey dragged back to the lair. Despite their bestial appearance, the yeth hound is rather intelligent, even if it does little with its intellect but devise and carry out ingenious, hateful plans to torment and horrify its prey before it finally strikes.

Yeth hounds can often be found in the company of night hags or evil hunters. Yeth hounds hate other canine monsters such as barghests and worgs, and attack them on sight if they have the advantage of numbers. They are often associated with particularly bestial demons, and can be found serving demon cults as guardians and trackers. A gift of a yeth hound companion to a particularly successful cult is sure sign of favor in the eyes of a demonic patron. A cult with yeth hounds granted to them in this manner must take care to retain this favor, for if they displease their demonic patron, the hounds could turn on them.

Yeth hounds inhabit secluded dens in remote wilderness areas far from bothersome civilization. These dens are always subterranean, far removed from the hated sunlight. Yeth hounds range great distances from their dens during their nightly hunts, and have been known to carry kills for miles just for the comfort of consuming a fresh meal in their lair. The sight of a yeth hound loping through the sky with a body clenched in its jaws is unsettling indeed.