So many game settings draw heavily on Tolkien. Even when they try to move away from him, like Dark Sun, the tendency is toward the human-dwarf-elf-hobbit combination being the core, with only minor deviations like the cannibal halflings of Dark Sun the tinker gnomes and kender of Dragonlance.
I want to try something different. My initial tendency is to avoid non-human species entirely, but I understand the motivations of some players to get away from the baseline human, or at least to provide some variety like Pendragon does by highlighting the different culture groups such as Britons and Saxons. What I want, then, is to create a situation where I can sort of mythologize the varieties of humans that once coexisted, with a couple of curve balls for spice. So, I'll start by having the three - four! or more! - species of genus Homo that were around a mere few tens of thousands of years ago. Obviously, H. sapiens represents the human baseline. The other three major lines are H. neanderthalensis and Denisovans, which for simplicity I'll just say are H. longi even if the final science might not be in yet, plus the surprising H. floresiensis and its close cousin, H. luzonensis. Rather than using the cumbersome taxonomy, I'll rename them all from the human point of view. Neanderthals will become ogres or trolls, drawing on the fairy-tale magical, cannibal ogre. Not that they will necessarily be cannibals! It's the perception of humans about their different neighbors. The Denisovans will be called elves, or perhaps oni, and they will be differentiated in this setting by having a noticeably longer lifespan - perhaps 150 years in comparison to the human 70-ish, or perhaps more than that. Floresiensis and luzonensis will be woodwoses, little, furry, hidden folk. In the setting, ogres, elves, and humans will interbreed, and so there will be half-elves (human-Denisovan), half-ogres or sometimes "orcs" (human-Neanderthal), and dark elves (Neanderthal-Denisovan).
I actually want to move away from that core of different human species, too. The easy one to include might be Gigantopithecus as a species of giant ape, but more like giant orangutans than something gorilla-like or sasquatch/yetis. And I'll make them into wise forest hermits, as the humans of the setting stereotype them. And because they're something of a personal obsession, there will be a bipedal rabbit-folk I call the koni. Perhaps oddly, the koni are the closest this setting will have to hobbits, living mildly sybaritic lives in holes in the ground. Koni are inspired by both medieval marginalia and Watership Down, so imagine a people with both warriors and seers, and with an inventive streak too.
And as I sat with these, thinking in particular about the forest giants, I decided that I wanted sapient, speaking, tool-using tribes of gorillas, which will be called the mountain-folk. It's the pulp-fantasy feel that I don't want to ignore. No doubt there are also other, more monstrous and animalistic apes in the setting, or in parts of it.
Speaking of animals, there will be Megalania, Varanus priscus, as dragons. Venomous monitor lizards up to 7 meters long certainly fit that description! And because they match the theme, there will be predatory flightless birds modeled on Phorusrhacidae, as well as a more domesticable flightless bird species of Gastornis, not unlike the horseclaws of Nausicaä of the Valley of the Wind.
