Where do the 'Mordenkainen's Tome' Elder Evils come from?

[Khisanth the Ancient]

Page 237 of Mordenkainen's Tome of Foes (Star Spawn entry) has a long list of Elder Evils.

Dendar the Night Serpent and Kezef the Chaos Hound are from FR, I believe. Tharizdun the Elder Elemental Eye is Greyhawk. I think the Queen of Chaos is from "The Rod of Seven Parts".

From 3E Elder Evils book:
Ragnorra the Mother of Monsters
the Hulks of Zoretha
Kyuss the Worm that Walks (originally from Greyhawk material)
Atropus the World Born Dead
Pandorym the Utter Annihilation
Father Llymic, the Alien Thought Given Flesh
Zargon the Returner (originally from B4 The Lost City)


So that leaves the following mysterious...

Ityak-Ortheel the Elf Eater
Borem of the Lake of Boiling Mud
Camnod the Unseen
Holashner the Hunger Below
Piscaethces the Blood Queen
Shothotugg the Eater of Worlds
Y'chak the Violet Flame
Bolothamogg who Watches from Beyond the Stars
Hargut of the Gray Pestilence and Haask the Voice of Hargut
Haemnathuun the Blood Lord
Maram of the Great Spear
Tyranthraxus the Flamed One

Does anyone know where these come from/where to find more information?

 

[pukunui]

Tyranthraxus is FR. See Phlan and the Pools of Radiance.

 

[Demetrios1453]

Ithyak-Ortheel and Borem are both FR as well, the former from the Moonshae Trilogy, and Borem was a being that Bane, Bhaal, and Myrkul slew on their path to become deities (but elder evils of course rarely remain dead).

Piscaethces has long been the aboleth patron for D&D in general. Looking it up, she first appeared in the Night Below supplement, which is setting-neutral.

 

[Greenstone.Walker]

Does anyone know where these come from/where to find more information?

Ummm...... Google?

Seriously, a few seconds of work found me information on these (mostly at the at the Forgotten Realms Wiki). For example, Maram of the Great Spear. The Wiki pages also include references, such as Brian R. James and Matt James. "Monument of the Ancients." Dungeon #170.

 

[the Jester]

Tyranthraxus is FR. See Phlan and the Pools of Radiance.

I could be wrong- but isn't Tyranthraxus originally from Mystara? I believe he/it is from, or at least described in, the old Immortals Set.

 

[pukunui]

I could be wrong- but isn't Tyranthraxus originally from Mystara? I believe he/it is from, or at least described in, the old Immortals Set.

I haven’t any idea. I only know the name from the Pools of Radiance series.

 

[Khisanth the Ancient]

Thank you!