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Greyhawk Deity
Olhydra, as depicted in Dungeon #199 (2012). Art by Tyler Jacobson.
Title(s) Princess of Evil Water Creatures, Princess of Watery Evil, Mistress of the Black Tide
Home Plane Elemental Plane of Water
Power Level Archomental
Gender Female
Alignment Neutral evil
Portfolio Evil water creatures
Domains Evil, Water
Alias(es) Alyolvoy (possibly)
Superior Elder Elemental Eye

Olhydra is an archomental. Her symbol is a blue-green square. It's possible that Alyolvoy, an evil archomental of water mentioned in Dungeon #37, is an alias of Olhydra.


Olhydra appears as an endlessly breaking wave of water, an amorphous blob with almost-human features buried within its depths. She is about 20 feet wide and weighs 5,000 pounds. She may also appear in other forms: a mass of swirling sea water, a feminine, half-human and half-pleiosaur creature with tentacles for hair and a semi-transparent liquid body, or as a beautiful sea nymph with blue skin and swirling, gray-green eyes.


Olhydra harbors an intense hatred of Imix and schemes to destroy him. Along with Imix, Yan-C-Bin, and Ogrémoch, she once pursued the artifact known as the Egg of the Phoenix. One of her greatest allies is Dagon, and rumor has it that she and Dagon may have spawned twin daughters. She occasionally comes into conflict with Blibdoolpoolp, Eadro, and Persana, but gives little thought to Ben-Hadar.

Olhydra is served by undead dinosaurs, kapoacinths (aquatic gargoyles), evil water elementals, water grues, water mephits, orlythys, renegade hezrou that she's lured away from Demogorgon, tojanidas, callers from the deep, and lesser water weirds. A triad of sea hags known as the Blue Coven also serves her; the three have merged into an entity with three bodies and a single mind.


Olhydra lives in the ruins of a castle made of living black coral, submerged in a great indigo lake, on the Elemental Plane of Water.


Olhydra's faithful include aboleths, sahuagin, scrags, anguillians, sea hags, krakens, seawolves, eyes of the deep, and many more. Pirates, wicked sea druids, and mariners flock to her cause, and she has one of the biggest followings among the evil elemental cults.


Olhydra's clerics, those who wear clothes, wear robes with blue trim. Many carry around small jugs of sea water for the purpose of special ceremonies and blessings.


Followers of Olhydra honor their mistress by drowning their enemies in seawater. The most powerful of these sacrifices are said to be given life anew by Olhydra to serve as her knights.


Olhydra01.jpg Olhydra02.jpg


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