Three Races
Three Races - Gargoyles, humans, and Oberon's Children, the three known sentient species upon Earth. Gargoyles were the first to evolve, followed by humans. Greg writes, "the Children incubated in magic and "evolved" third", hence another name for them is 'the Third Race'.
New Olympians are a hybrid race, and fall somewhere between humans and Oberon’s Children, rather than as a separate race of their own. There was another race preceding all three of these, nicknamed the Lost Race, but it is now extinct; we do not as yet know what it was like, or how it ceased to exist.