Dark Hounds

Darkhounds are a race of Shadowspawn used by the Dark One. They are about the size of a small horse and look vaguely like a dog. Darkhounds typically run in packs of ten to twelve, though a pack may be as large as fifty hounds. The saliva of a darkhound is an acid that causes bruising and burns which spread quickly, and a few drops are enough to kill a person. Darkhounds (or at least a subspecies Rand al'Thor fights at Rhuidean) are seemingly solid but if they are chopped into bits the parts liquefy, pool, and reform into the darkhound once again. They will not reform on the ancient symbol of Aes Sedai. Their liquified parts will run off the symbol before reforming. The darkhound leaves no tracks on dirt, grass or snow; but if it steps on stone it leaves footprints. Balefire is the only reliable way to permanently kill one, though Perrin (with Moiraine in party) fought Darkhounds outside of Illian, and killed one with several arrows to the face.

Darkhounds are created by an existing darkhound consuming the soul of a wolf. The wolves themselves refer to them as Shadowbrothers.

Masuri, a Brown Aes Sedai, has researched Darkhounds and claims to have crossed the paths of seven different packs. She says that the number of packs in existence is in dispute, with some sources saying only seven packs exist, while others claim nine, thirteen, or more. Some ancient sources even state that at the time of the Trolloc Wars, there were "a hundred packs" and "in numbers like unto the nightmares of Mankind." See Crossroads of Twilight for a more detailed discussion.