BOZ
Creature Cataloguer
Hola! 
Over in this thread we are figuring out how best to convert the various fiend lords and other high level beings to 3.5. We won’t be bothering with anything in an official WotC book such as BoVD or D&DG, or the Tome of Horrors. This includes only “monstrous” sort of beings, not just humans with a whole lot of character levels, special feats, and templates and such. Elminster, therefore, is not a concern, but a unique dragon, or a magical beast as powerful as the Tarrasque would be acceptable. Liches and lycanthropes are not a concern either, as these are really just NPCs with templates. See if you can add anything to the list (I know you can!).
Already in the Creature Catalog, we have:
Demon (Miska the Wolf-Spider)
Demon (Queen of Chaos)
Demon Lord (Zuggtmoy)
Devil (Duke Alastor)
Devil (Duke Baalberith)
Devil (Duke Baalzephon)
Devil (Duke Caarcrinolaas)
Devil (Duke Focalor)
Devil (Duke Melchon)
Devil (Duke Zimmimar)
Devil (Princess of Hell- Baalphegor)
Devil (Princess of Hell- Glasya)
Devil: Selm (Prince of the Possessors)
Elemental (Quasi-Mineral- Crystalle)
Elemental Lord (Cryonax)
Elemental Lord (Ogremoch)
Elemental Lord (Olhydra)
Elemental Lord (Yan-C-Bin)
Modron (Primus)
Slaad Lord (Chourst)
Slaad Lord (Rennbuu)
Besides that there are, for starters:
Bitru (a Gygax devil lord from Dragon 75 that never made it into the MM2)
Amduscias, Malphas, Nergal, Bist, Caim, Lilis, Arioch, Biffant, Merodach, Alocer, Naome, Chamo, Balan, Bathym, Gaziel, Cozbi, Gorson, Herodias, Agares, Machalas, (from Dragon 75, by Ed Greenwood)
Lilith, Tartach, Bileth, Baftis, Neabaz, Barbatos, Abigor, Zepar, Bele, Adonides, Barbas, Bifrons, Bensozia, Adramalech, Phongor, Buer, Bune, Morax, Rimmon, Zagum (from Dragon 76, by Ed Greenwood)
Armaros, Azazel, Cahor, Dagon, Duskur, Kochibel, Malarea, Nisroch, Rumjal, Gargoth (From Dragon 91, by Ed Greenwood – although Gargoth appeared in the 2nd edition as Gargauth, a demigod)
Archomentals (Good) (Ben-Hadar, Chan, Sunnis, Zaaman Rul)
Eltab (Spellbound boxed set)
Kerzit (Mordenkainen’s Fantastic Adventure)
And besides demon lords, there are all sorts of other unique things out there
Various beings from old D&DG/Legends and Lore (not merely just the NPCs)
Various other Forgotten Realms beings
I’m sure there are many more to list.

Over in this thread we are figuring out how best to convert the various fiend lords and other high level beings to 3.5. We won’t be bothering with anything in an official WotC book such as BoVD or D&DG, or the Tome of Horrors. This includes only “monstrous” sort of beings, not just humans with a whole lot of character levels, special feats, and templates and such. Elminster, therefore, is not a concern, but a unique dragon, or a magical beast as powerful as the Tarrasque would be acceptable. Liches and lycanthropes are not a concern either, as these are really just NPCs with templates. See if you can add anything to the list (I know you can!).
Already in the Creature Catalog, we have:
Demon (Miska the Wolf-Spider)
Demon (Queen of Chaos)
Demon Lord (Zuggtmoy)
Devil (Duke Alastor)
Devil (Duke Baalberith)
Devil (Duke Baalzephon)
Devil (Duke Caarcrinolaas)
Devil (Duke Focalor)
Devil (Duke Melchon)
Devil (Duke Zimmimar)
Devil (Princess of Hell- Baalphegor)
Devil (Princess of Hell- Glasya)
Devil: Selm (Prince of the Possessors)
Elemental (Quasi-Mineral- Crystalle)
Elemental Lord (Cryonax)
Elemental Lord (Ogremoch)
Elemental Lord (Olhydra)
Elemental Lord (Yan-C-Bin)
Modron (Primus)
Slaad Lord (Chourst)
Slaad Lord (Rennbuu)
Besides that there are, for starters:
Bitru (a Gygax devil lord from Dragon 75 that never made it into the MM2)
Amduscias, Malphas, Nergal, Bist, Caim, Lilis, Arioch, Biffant, Merodach, Alocer, Naome, Chamo, Balan, Bathym, Gaziel, Cozbi, Gorson, Herodias, Agares, Machalas, (from Dragon 75, by Ed Greenwood)
Lilith, Tartach, Bileth, Baftis, Neabaz, Barbatos, Abigor, Zepar, Bele, Adonides, Barbas, Bifrons, Bensozia, Adramalech, Phongor, Buer, Bune, Morax, Rimmon, Zagum (from Dragon 76, by Ed Greenwood)
Armaros, Azazel, Cahor, Dagon, Duskur, Kochibel, Malarea, Nisroch, Rumjal, Gargoth (From Dragon 91, by Ed Greenwood – although Gargoth appeared in the 2nd edition as Gargauth, a demigod)
Archomentals (Good) (Ben-Hadar, Chan, Sunnis, Zaaman Rul)
Eltab (Spellbound boxed set)
Kerzit (Mordenkainen’s Fantastic Adventure)
And besides demon lords, there are all sorts of other unique things out there
Various beings from old D&DG/Legends and Lore (not merely just the NPCs)
Various other Forgotten Realms beings
I’m sure there are many more to list.
