Originally Posted by
Jokubas
Here's a huge list of potential subraces (defaults in italics) based on currently existing, visually distinct, humanoid creatures, whether or not they're currently friendly.
Human: Human
Dwarf: Ironforge, Wildhammer, Dark Iron, Earthen, Frostborn, Iron Dwarf
Night Elf: Night Elf, High Elf, Nightborne, Nightfallen, Withered, Felborne, Satyr
Gnome: Gnome, Mechagnome, Leper Gnome, Sand Gnome
Draenei: Draenei, Army of the Light, Man'ari, Broken, Lost One
Worgen: Gilnean, Cursed Night Elf
Pandaren: Pandaren
Orc: Orc, Mag'har, Blackrock, Shattered Hand, Fel Orc, Mok'Nathal
Undead: Lordaeron Human, Undead High Elf
Tauren: Tauren, Highmountain, Taunka, Yaungol
Troll: Jungle, Forest, Ice, Dark, Sand, Zandalari
Blood Elf: Blood Elf, Wretched, Felblood Elf, Darkfallen
Goblin: Goblin, Gilgoblin, Hobgoblin
I tried to keep this list to the most directly related to each race and most of them come off of the parent race (which is also part of the reason why I put the nightborne with night elves rather than blood elves for now). I'm sure I still missed some things. As it is, I left off the ones I mentioned earlier as being related but often asked for as distinct races. I'll do those below.
Vrykul (Origin of humans): Vrykul, Iron Vrykul, Frost Vrykul, Kvaldir
Ogre (Origin of orcs): Ogre, Two-Headed, Ogre Lord, Mok'Nathal
Naga (Originated from night elves): Naga, Naga Lord
Depending on how such a system is handled, you could make logical extrapolations for some races, and not necessarily need them for others. Mag'har orcs, for example, are just a different skin color choice. If some (or all) subraces just have alternate customization, then you could do a ton for each orc clan and even separate the human kingdoms that way (perhaps even creating a non-cursed Gilnean). I didn't mention highborne here despite it being a popular choice because there is no confirmed visual difference between them and the base night elves, but if subraces were handled on that level, they could easily have a different set of choices, like gaudy jewelry or something.