Heh? Perhaps I should release my "Experiments" mod but then again it's an insult to game balance since I just use it to try out concepts.
Units I made that seem to be somewhat functional without turning the balance:
Abyssal line creatures - Created by using the sprites of aquatic aliens from Duke Nukem.
Abyssal Terror, Size 6 amphibian "army scythe" with a lot of hitpoints and areashock ability. Costs a fortune but is essentially a SC pretender for sale. Drains the economy and quickly racks up the afflictions. But can potentially break a massive formation in the endgame. Currently assigned to Atlantis.
Abyssal Scourge, Size 4 unit that's essentially an amphibious medium cavalery in function. Berserk +3 and venomous. Assigned to the slow moving Atlanteans.
Abyssal Maw, Size 4 amphibian slowmoving flyer with big bite, tentacles and Lifedrain. Assigned to R'Lyeh.
Mythical Creatures - Derived from Hexen and Heretic sprites as well as others less known. Pretenders so far since I don't know how else to create singular creatures in the game.
Earthsunderer - Giant Minotaur with big hammer. Trampler, Berserk and very strong. My switch for the somewhat silly Lord of Fertiliy.
Reaper - Giant Satyr with Scythe of Slaying. Death and Nature Pretender for the cycle of life. My switch for the Father of Serpents.
Gaeas Avenger - Female Nataranja in red bikini. Unarmed but with earth and nature magic. Switch for the Great Mother.
Earthfires Fury - Flaming Giant Gargoyle. A bit on the higher end of power tough. Fire and Earth pretender with heataura, high protection and firebreath. Doesn't heal and weak against cold. Switch for Phoenix.
Draconian Empress - Three headed giant draconian/hydra hybrid pretender with no magic. Basically a variant of SC. Switch for Manticore.
Targeteer - Robinhood style pretender with 20 precision. All other stats are very poor though. Switch for Crone.
Undermountain King - Big Dwarf pretender complete with Axe, Shield and Beard. Earth Pretender that can function as a mini SC with a little planning.
Wanderer - Hooded Mage with fire, air, death magic. Switch for Frost Father.
Icewind Lord - Nemesis of Earthfires Fury. Giant Icecreature with frostaura, high hitpoints but no healing and fire weakness. Air and Water pretender.
That's all I feel are working as for now. Got a Giant Metal Flying Skull, Imp and Devourer sprites from old Doom, Giant Mummy, Giant Fire Elemental and Big Demonic Flying Head with Arms Thing left to assign names and stats.