Myrmyxicuses were ancient, aquatic tanar'ri demons both awful to behold and devastating to encounter. The dreaded leviathans were infused with unholy energy, and ruled the depths of fiendish seas as terrible tyrants and masters of great slave empires.
Myrmyxicuses were massive demons, measuring nearly 25 ft (7.6 m) long from head to tail. Their heads were like those of some prehistoric reptile of the sea, with tiny, black eyes and a fanged snout, as well as three pairs of curling, ram-like horns.
Their bodies were green and greasy, with a row of tall spines running down the back and a muscular, humanoid torso with four arms arranged symmetrically around the chest. Six tentacles like those of an octopus similarly ringed their waists, marking their long, eel-like lower halves ending in a tail with the mouth of a slavering lamprey at the tip.
The only true master of a myrmyxicus was itself, the foul creatures refusing to serve any other being, at least for very long. Few beings could match the horrible wrath of such creatures when they became enraged, and though tyrannical, some were known to infrequently commit random acts of violence on passersby before slinking back into the depths. They were incredibly knowledgeable and cunning creatures with a powerful force of personality, and were not to be mentally underestimated.
Myrmyxicuses lacked the vast array of spell-like abilities seen in other powerful demons, though they did still have a potent retinue. They could replicate the effects of cause fear, charm person, charm monster, freedom of movement, telekinesis, teleport without error, and true seeing at will, and control water, control weather, greater dispelling, unholy aura, and unholy blight three times per day. They also had the typical tanar'ric ability to summon other demons once each day, in their case choosing between a school of 2-12 skulvyns or a hezrou, succeeding slightly more than half the time.
Despite this lack of spell-like diversity to rely upon, myrmyxicuses didn't typically need such powers, instead utilizing deadly and varied melee abilities. Their tentacles could easily grab and constrict smaller opponents, and a strike from their tails could drain a victim's sense of self and convert it into life force for the myrmyxicus. As aquatic tanar'ri, they could travel through water much faster than they could on land. Oddly enough, they could also fly, albeit poorly, through natural magic.
Myrmyxicuses were profane creatures whose very being was permeated and protected by unholiness. Every minutes they could spew out a cone-shaped cloud of vile, black vapor that nauseated all in its wake and was lethal to beings of good. Their thick, tar-like blood was similarly toxic, and so piercing or slashing their horrifying forms would spray the fiendish ichor on the assailant. They could also infuse any scythe they touched, presuming it was of sufficient quality, with unholy magical energy for as long as they held it, although infusing a scythe took a few seconds, they could only empower one at a time, and had a limit of infusing four at once.
Myrmyxicuses typically spread out their attacks between as many enemies as possible, only focusing on singular foes in the rare situations where an individual foe posed a significant challenge.
Myrmyxicuses ruled vast portions of Abyssal oceans from immense, floating citadels, palaces constructed from millions of tons of fish skeletons, razor-sharp shells, and piercing coral. Inside the galleries and curving halls of these structures were thousands of captives, ranging in strength and origin from unfortunate mortals captured during a Material Plane raid to demon lords that recklessly challenged a myrmyxicus slave master. Rather than simply keep captured servitors, each myrmyxicus supplied slaves to others throughout the cosmos for a variety of purposes, including conscripts for wars, workers for factories, or fighters for arenas. Many sought to expand their slave empires by finding ways to move their citadels to other layers of the Abyss or other planes entirely, and could spend ages doing so.
Myrmyxicuses were known to keep demonic company as weak as skulvyns and as dangerous as the water lords known as wastriliths. They were feared and respected by nearly all beings they encountered, and even the most pompous balor knew to give them their due. It was for this reason that no demon lord ruled the Abyssian Ocean, the bottomless depths that touched all the seas of the Abyss's infinite layers. Even undersea sovereigns like Dagon and Demogorgon, though they sometimes traversed it under special compact, wouldn't dare to enact their sinister designs there, for the Soulless Sea was their dominion. The Prince of Demons was even known to correspond with some of them (and some myrmyxicuses were known to plot against him).
Despite this reputation, myrmixcuses were by no means invincible. Even despite their tanar'ric nature, they still paid tribute to the obyrith Dagon when treading his Shadowsea, if only to keep him appeased.
Even disregarding the presence of Dagon, myrmyxicuses hesitated before entering the Shadowsea due to persisting rumors of giant clouds of undying pollution that stripped the flesh of all it touched. Aside from the various layers of the Abyss, myrmyxicuses could also be found in the River Styx and the Fated Depths.
Myrmyxicus were primeval tanar'ri, one of the earliest breeds to ever haunt the Abyss. They came into being when the process of mortal souls becoming demons was still stabilizing, and the raw chaos of the Abyss left them primal and monstrous creatures with few humanoid aspects.
- Originally in the Fiend Folio, the CR was given as 21.
Caligrosto • Dybbuk • Guecubu • Manitou
Adaru • Alkilith • Armanite • Arrow demon • Babau • Balor • Bar-lgura • Bulezau • Cerebrilith • Chasme • Dretch • Gadacro • Glabrezu • Goristro • Hezrou • Jovoc • Kastighur • Klurichir • Lilitu • Mane • Marilith • Maurezhi • Mavawhan • Molydeus • Myrmyxicus • Nabassu • Nalfeshnee • Palrethee • Rutterkin • Solamith • Sorrowsworn • Spyder-fiend • Succubus • Uridezu • Vrock • Yochlol
Draudnu • Ekolid • Golothoma • Laghathti • Sibriex • Uzollru • Verakia • Wastrilith
Abyssal chicken • Abyssal scavenger • Abyssal wretch • Abyssal wurm • Bebilith • Bonegouge assassin • Deathdrinker • Demon spawn • Ferrolith • Ghour • Haures • Immolith • Jarrlak • Kazrith • Mahataa • Maw demon • Nashrou • Quarrak • Quasit • Rageborn • Retriever • Shadow demon • Shoosuva • Skulvyn • Tomb demon • Voracalith • Whisper demon
- Eric Cagle, Jesse Decker, James Jacobs, Erik Mona, Matthew Sernett, Chris Thomasson, and James Wyatt (April 2003). Fiend Folio. (Wizards of the Coast), pp. 52–54. ISBN 0-7869-2780-1.
- Ed Stark, James Jacobs, Erik Mona (June 13, 2006). Fiendish Codex I: Hordes of the Abyss. (Wizards of the Coast), p. 157. ISBN 0-7869-3919-2.
- Ed Stark, James Jacobs, Erik Mona (June 13, 2006). Fiendish Codex I: Hordes of the Abyss. (Wizards of the Coast), p. 109. ISBN 0-7869-3919-2.
- Ed Stark, James Jacobs, Erik Mona (June 13, 2006). Fiendish Codex I: Hordes of the Abyss. (Wizards of the Coast), p. 111. ISBN 0-7869-3919-2.
- Ed Stark, James Jacobs, Erik Mona (June 13, 2006). Fiendish Codex I: Hordes of the Abyss. (Wizards of the Coast), p. 142. ISBN 0-7869-3919-2.
- Ed Stark, James Jacobs, Erik Mona (June 13, 2006). Fiendish Codex I: Hordes of the Abyss. (Wizards of the Coast), p. 61. ISBN 0-7869-3919-2.
- Ed Stark, James Jacobs, Erik Mona (2006-06-20). Fiendish Codex I, Part 2: The Lost Annals: Additional Layers. Wizards of the Coast. Archived from the original on 2014-02-02. Retrieved on 2017-09-15.
- Richard Baker, James Wyatt (March 2004). Player's Guide to Faerûn. (Wizards of the Coast), p. 152. ISBN 0-7869-3134-5.
- James Jacobs (September 2007). “The Demonomicon of Iggwilv: Apocrypha”. In Erik Mona ed. Dragon #359 (Paizo Publishing, LLC), p. 44.