Leonin
There are two distinct ethnicities, both of which have articles that go into more depth about their individual customs and naming conventions.
Below you can find a wealth of information relating to this species and their cultural norms and other additional information.
Basic Information
Anatomy
Although they stand taller than most humans, Leonin age at about the same rate. They are bipedal felines that have tails. Their hands are as nimble as other humanoids', but Leonin also have retractable claws, which are natural weapons.
Darkvision. You can see in dim light within 60 feet of you as if it were bright light and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.
Claws. Your claws are natural weapons, which you can use to make unarmed strikes. If you hit with them, you can deal slashing damage equal to 1d4 + your Strength modifier, instead of the bludgeoning damage normal for an unarmed strike.
Hunter's Instincts. You have proficiency in one of the following skills of your choice: Athletics, Intimidation, Perception, or Survival.
Daunting Roar. As a bonus action, you can let out an especially menacing roar. Creatures of your choice within 10 feet of you that can hear you must succeed on a Wisdom saving throw or become frightened of you until the end of your next turn. The DC of the save equals 8 + your proficiency bonus + your Constitution modifier. Once you use this trait, you can't use it again until you finish a short or long rest.
Ecology and Habitats
Vast open plains, teeming with game. Leonin cope best in regions that are large and flat, as they can rely more upon their senses that are well adapted to these kinds of conditions.
Flat landscapes allow Leonin to hear from longer distances, and to help track and trace smells.
Dietary Needs and Habits
Leonin are obligate carnivores, and therefore have a picky appetite to ensure they have a healthy and varined intake of vital nutrients.
Biological Cycle
Leonin shed all year round and their coat shows little adaptation towards varying weather conditions. Generally Leonin don't cope well outside of traditionally warmer climates, so regions with high altitudes or strong seasonal shifts in weather are often inhabitable without proper preparation and climate regulation like warmer coats and heated housing.
Additional Information
Social Structure
Leonin rely on themselves and their prides. A pride is bound together by the experience of a shared challenge and, in particular, the sacred act of the hunt.
Geographic Origin and Distribution
The leonin guard the shining lands of Oreskos, a golden plain where even the gods rarely trespass.
Perception and Sensory Capabilities
At night, a reflective coating on the back of the eye helps to reflect the moonlight, giving them darkvision. This makes a Leonin’s eyesight eight times better than that of a human. They also have a white patch of fur below their eyes which helps to reflect even more light back into the eye.
Leonin have what's called a Jacobson’s organ. This is a small area in the roof of the mouth that allows them to ‘taste’ smells in the air. By showing their teeth and sticking out their tongues, they are able to catch hold of smell to work out if it’s coming from something worth eating which also makes them good at recognising the general tones and potential origin of a smell. E.g. death/decay, herbal, floral, and more.
Leonin have a good sense of hearing. They can turn their ears in different directions to listen to sounds all around them and are able to hear their prey from a mile away.
Civilization and Culture
Naming Traditions
Along with their personal names, leonin identify themselves by their pride. A member of the Flintclaw pride with the personal name of Ziore, for example, would likely style herself as Ziore of the Flintclaw..
Names tend to be short or comprised of a maximum of three sylablles.
Pride names tend to have a significant historical meaning relating to the prides ancestral roots.
Common Etiquette Rules
Other peoples often perceive leonin as quick to take offense, intolerant of criticism, or belligerent. The truth is that many leonin simply enjoy fighting, whether verbal or physical. They take pleasure in argument, wrestling, sparring, and even battle, enjoying the opportunity to exercise their minds and bodies.
It follows, too, that leonin aren't inclined to carry grudges. A warrior might react with sudden violence to an insult, but when the fight is over (and the leonin's superiority proven), the insult is forgotten—along with the vanquished foe.
History
Few leonin devote themselves to the service of the gods. Centuries ago, the leonin worshiped the same gods that humans do, but after many of their prides suffered depravities at the hands of the tyrant Agnomakhos, most leonin rejected the gods. It's not that they deny the existence of deities; they merely see the gods as mercurial and ultimately unworthy of adoration.
Historical Figures
Ajani
Interspecies Relations and Assumptions
Prides of these nomadic, lion-like humanoids rarely interact with other peoples, having all they need in their shimmering homeland and knowing the treachery of strangers. Still, some leonin wonder what lies beyond Oreskos' border mountains and seek to test themselves in a wider world.
Leonin often act with confidence, which can come off as imperiousness. While this can reassure their allies, it can also suggest defiance in the face of what they perceive as imposed authority or unworthy experts.
Muscular and lean. As Leonin prides are mostly nomadic a lot of the tribe members have a very varied and hands on role within the pride, meaning that staying fit and active is a core element of Leonin society.
Tawny or golden fur, and rarely dark brown, black, or even white fur. The latter is mostly reserved for the various ethnicities.
In some prides subtle dappling can be seen under their coat.