Canoloths were the loyal hounds of the yugoloths, serving both as guardians and trackers for their masters. Although less populous and technically of lower status than the mezzoloths, they were treated far more favorably and regarded as valued parts of any yugoloth mercenary legion.
Canoloths stood 4 ft (1.2 m) tall and were 6 ft (1.8 m) in length, resembling giant canines somewhere between mastiffs and bulldogs and that hosted various insectioid traits, such as their chitinous armor plating. They were hulking, 400 lb (180 kg) beasts with four clawed feet that they dragged along the ground with their short, stubby forelegs.
Within their mouths were two sets of teeth, with the first horizontal and the set behind it being vertical. Carelessly lolling out of both their massive maws was a barbed tongue, several inches thick and coated in sticky slime, that could flick outwards somewhere between 20‒30 ft (6.1‒9.1 m) at any moment. Their gaping nostrils laid at the front of their skulls, sniffing and snorting at the ground as they moved. This was because canoloths lacked eyes, navigating by their powerful olfactory and auditory senses.
Among the various yugoloth castes, canoloths were the most loyal, however this loyalty was not to be confused with discipline. Their obedience partially stemmed from their slothfulness, as they preferred to do as little work as possible. The other reason was that they were remarkably unintelligent and followed their masters' orders to the death. Although petty and malicious, they were also fairly tolerant of many fiendish denizens and might find themselves joining with abyssal creatures.
The senses of a canoloth were strong enough to pinpoint creatures by smell and sound, easily compensating for their lack of eyesight. Invisibility, gaze attacks, visual illusions, and other effects reliant on sight were useless against them. At the same time, one could "blind" a canoloth by negating, overpowering, or bypassing their other senses. Through removing one's own scent, blocking the canoloth's nostrils, or filling the air with an overwhelming odor, such as heavy incenses or noxious clouds of gas, one could reduce a canoloth's ability to perceive a target. Moving silently, blocking their ears, or making a loud enough noise had a similar effect, although yelling was not enough to accomplish anything outside of making oneself obvious. Negation of both senses rendered canoloths truly blind and failing this they could be tricked through the use of misleading noises and smells.
In terms of offense, canoloths were equipped with clawed paws they could use to tear foes limb from limb, although their armor-crushing jaws were far more deadly. Canoloths generally had no need to move in order to rip foes apart, as a combination of barbs and slime on their whip-like tongues let them drag any threat toward their waiting mouths. Foes would have trouble escaping or bypassing a canoloth even if not for their keen senses and entangling tongues. They emitted a dimensional-locking field nearby themselves, foiling any attempts to teleport in or out of the space. If desired, they could try to summon a small group of mezzoloths or pack of canoloths to aid them.
Canoloths had a simple but effective combat strategy, pinpointing their enemies with their unusual senses before swiftly reeling them in with their tongues. Their next step was generally dependent on the situation. If not instructed otherwise canoloths were usually content to harmlessly hold onto an intruder rather than kill them. If under orders, however, they would rend and chew until their former targets became meals. If surrounded or unable to reach their foes they normally resorted to making unnerving yowls before trying to lash out.
Canoloths served as the hunting dogs of the yugoloths, acting as scouts, trackers, retrievers and assassins. They also made use of their uncanny perception to work as guardians and bodyguards, although they preferred to work as guards of precious treasures and crucial sites.
While mezzoloths and dhergoloths made up the rank-and-file soldiers in yugoloth armies, canoloths were fewer in number but more valuable than individual soldiers. Their ability to gather intelligence was a great aid to both piscoloth and nycaloth commanders. Their value to their leaders despite their relative weakness was well known to the canoloths and used to bully and annoy mezzoloths and hydroloths. It was not uncommon for greater yugoloths to keep a small pack of canoloths around, with arcanaloths and ultroloths even saddling them and using them as mounts. Mezzoloths often trained them to act as savage pets and sold them to whoever might desire one. Like guardian yugoloths, they were occasionally summoned during attempts by mortals to conjure a yugoloth without knowing the true name of one.
When not employed, canoloths roamed the Lower Planes looking for victims to kill and torment. They were driven by a primal desire for flesh and instinctively formed feral packs both with those of their kind and various other creatures. They were commonly seen within the Gray Wastes and Gehenna, but were also known to traverse the Blood Rift.
It was postulated that canoloths were created from mezzoloths that showed enough courage but this claim was somewhat unsubstantiated. At one point, it was unknown if this was a required step to power like the dhergoloth caste or an intentional punishment like the skeroloth caste, although eventually it was determined to be demotion. Regardless, all yugoloths dreaded being turned into a canoloth as, despite the improved opinion, becoming one basically removed all of a yugoloth's status.
- Mike Mearls, Jeremy Crawford (May 29, 2018). Mordenkainen's Tome of Foes. Edited by Kim Mohan, Michele Carter. (Wizards of the Coast), p. 247. ISBN 978-0786966240.
- Richard Baker, John Rogers, Robert J. Schwalb, James Wyatt (December 2008). Manual of the Planes 4th edition. (Wizards of the Coast), pp. 120–121. ISBN 978-0-7869-5002-7.
- Andrew Finch, Gwendolyn Kestrel, Chris Perkins (August 2004). Monster Manual III. (Wizards of the Coast), p. 200. ISBN 0-7869-3430-1.
- Richard Baker (October 1995). Monstrous Compendium Planescape Appendix II. Edited by Karen S. Boomgarden. (TSR, Inc.), pp. 126–127. ISBN 0-7869-0173-X.
- Colin McComb (September 1997). Faces of Evil: The Fiends. Edited by Ray Vallese. (Wizards of the Coast), p. 70. ISBN 0-7869-3430-1.
- Colin McComb (September 1997). Faces of Evil: The Fiends. Edited by Ray Vallese. (Wizards of the Coast), p. 76. ISBN 0-7869-3430-1.
- Todd Stewart (September 2007). “Campaign Workbook: Wandering Monster - Dhergoloth”. In James Jacobs ed. Dungeon #150 (Paizo Publishing, LLC), pp. 124–125.
- Paul S. Kemp (February 2006). Resurrection. (Wizards of the Coast), p. 210. ISBN 0-7869-3981-8.