So, I went with this idea.

Each of the environments are opposite, we have cold lands in the north, fiery lands in the south, deserty lands in the east, and jungly lands in the west.

Also, I went with, how can I make a cliche idea non-cliche?

Dragons. Not fire breathing winged things, these are giant, powerfully limbed komodo dragon style lizards, who, when fed a proper diet and properly trained can have an extraordinarily venomous bite as well as toxic breath.

The people here don't call themselves dragon riders, it is others who call them that, because these people have no language. Every single person in this culture has a symbiotic relationship with one of these dragons, and together they hunt and survive in the harsh jungle. Those that have the desire meet up at bi-yearly "festivals" or meets, around notable landmarks to have children, but otherwise, the only contact between members is generally territorial fights or passing each other by. The jungle, or perhaps their diet, has a strange effect on the growth of humans in the jungle, and they age to maturity swiftly in about three years, but likewise share the more limited lifespan of around 30 years of their companions.

When hunting, the human lays traps, prepares brews, readies camouflage, uses bows and spears, and chases prey towards the dragon. In return, the dragon protects the humans from the numerous powerful predators the jungle has. While the dragons are suspected to be more intelligent than other lizards, there is little reason to believe they are more intelligent than fiercely protective dogs.

The individual strengths of each human in the culture are significant, each one a master of the arts of herbalism, wilderness survival, archery, and other skills, to say nothing of their dragons. However, there are also no recorded instances of these people ever banding together against a threat in numbers more than the handful necessary to slay a river wurm, though there are few recorded instances of these people's history at all.