In my homebrew elves, dwarves, halflings, gnomes and orcs are known of the Divine Races. The Divine Races were created and placed on the world according to each of their gods. Humans (for want of a better term) evolved naturally and had to create their own gods.
Whenever a Divine race mates with another Divine race the result is a new race that breeds true. Some examples;
Halfling + dwarf = xeph
Dwarf + gnome = goliath
Elf + orc = drow
halfling + orc = goblin
elf + gnome = meaned
and so forth.
Human and divine races produce sterile half-breeds (half-elf, etc.). Various animal races (phanatons, bullywugs, etc.) come from the divine races influencing local animal populations through familiars, animal companions, awakened, and actual breeding over the centuries.
There are no warforged, but I did let one player play one (and see below).
Magic is split up into 6 types:
divine (cleric and paladin)
pagan (druid and ranger)
hermitic (wizard and wu jen)
psionic (psion, et al)
goetic (sorcerer and bard)
thaumaturgic (magister)
The first four are unchanged from the rules. Goetic means summoning and goetic practitioners must contact outsiders, elementals, spirits, etc. and make bargains to get their spells. (This is very much like the Warlock as described in CA. My warlock is actually a rune caster. Experts are debating if this should be hermitic or declared a 7th magic. But I digress.) Thaumaturgic magic is the Arcana Evolved variety and was discovered about 50 years ago by researches who thought that magical theory would be more elegant if there were 6 magics.
There actually is a 7th magic, eldritch, which are the corrupt and exalted spells from BoVD and BoED. Only one nation knows about it and they’re not telling.
The Divine races each worship their own pantheon. There is a human pantheon, but humans also follow dualism and monotheism. Interestingly, pantheists rejects the ideas of dualists and monotheists, while the dualists accept pantheists (because it fits into their view) but not monothiests, and the monotheists accept the others as merely flawed, but not invalid, ways of viewing religion.
The campaing is set during the 5th age, which started after the great flood and is the first time that dragons have been in the world.
Previous ages are:
1st Forbidden Empires – lots of Lovecraftian goodness without dragons
2nd Age of Reptiles - standard D&D with tortles, chelonians, skinks, lizard men, and ophidians replacing the standard PC races. But no dragons.
3rd Bug Empires - Dromites, thri-kreen, and others insectile races. But no dragons.
4th Mammal Empires – Elf, Dwarf, etc. But no Dragons
5th Human Empires – Same as 4th but with Dragons (the present)
The ages are defined by the rise and fall of civilizations. At the end of each age the inhabitants are wiped out and there is an Interregnum ruled by Dragons. The Ages and Interregna are (or were) completely unaware of each other. So when the 5th age started it looked like dragons appeared out of nowhere and to the dragons it looked like Elves and humans appeared out of nowhere.
I mention the other ages because there is time travel from one age to another. The 6th Age has splintered timelines (because PCs have yet to resolve certain issues in the present) and currently the Elan, Illumians, Cybermen, mind flayers, and time lords are all fighting for survivial (and have sent NPC adventurers to make sure their history is the right history.).
So to sum up: What makes my campaign special?
Lots of races, with a mechanic to explain the insane amount of speciation available
Time travel
That one warforged who came through a gate, got experimented on by grell, and is (or will be) the father of all Cybermen whether he likes it or not. (And I can’t wait to see the looks my player’s faces.)
Pell-Mell, I love that you did something with Gargoyles. I feel that they're just utterly neglected. Goblyn, that makes sense, I admit. I've seen several people tie elves to plants. 
