On our earth they're one group that falls under Werewolves (other groups include shifters and cursed people who are forced to change into wolves).
They live in any environment you'd expect wolves to be found, usually crepuscular but can be active during any time of day. They can eat any human food but their diet is very meat heavy. They prefer to eat meat raw but will cook it when they are with species who are grossed out by the idea.
Gestation is 9 months and the baby is weaned at 2 years. Babies can be born in either their fur (wolf) or skin (human). It depends on what form the mom was in when they were born and stay in that form until they are 3 years old. The mom stays in the same form as the baby as much as possible during this time. Babies in their skin learn to talk at the same age as humans but babies in their fur start talking soon after their first shift. By the time the child is 6 or so you can't tell which form a child spent their early years by their speech.
Adulthood is at 16 and female wolves tend to disperse soon after (except for Lunas who leave whenever the Luna of their clan says they are ready). Males however stay with their mom's clan until they find their mate. It is unknown how long they can live because once they hit their 4th century they leave their clan and even their mate and strike out on their own in wolf form. It's called Walking the Moon Path and no one (including themselves) know why they do this. There are, however, several legends about this. Its very rare to see one of these wolves but considered to be good luck by Moonrunners and anyone who know of them.
In their human shape, they look like regular humans, hair and eyes are any color you can find with humans. Women tend to be on the taller and bigger side of human norms but men fall more into human norms.
Their wolf form is roughly as large as their human form, looks bigger though thanks to the fur, they do look like wolves otherwise but with larger skulls for the brain. Their fur tends to be black/gray/white and their eyes are gold unless they are Lunas then they are silver.
Clothing
Babies born in their skin tend to be swaddled until they can turn over after which they wear clothing similar to human babies. Once old enough to change they tend to wear simple, easy to remove, tunics and pants or dresses. Tattoos and piercings are never worn (they don't work well with shifting) and very little jewelry. What jewelry they do wear is made of steel, or silver if the Luna, and tends to be simple. Usually with a lunar or nature motif and on leather cords that are tied so they can expand when shifting. Shoes are only worn if its really cold and are also easy to remove. All clothing is designed to rip at the seams and fall off them if they have to transform in their clothing.
Shifting
All Moonrunners can shift into either form freely during the night unless there is a full moon at which point they are compelled to shift into their fur. Children born in their skin and younger than 3 and the one who nurses them (usually their mom) are exempt from full moon shifting.
Most of them cannot shift when the sun is in the sky and for those who can it is difficult.
Healing & Magic
They are able to heal all injuries by shifting, unless caused by silver. This doesn't work with what few illnesses they are able to catch though.
Lunas are the only ones who can preform magic outside of shifting. They mostly practice healing and illusions but some are capable of doing other things. They are also immune to silver and can heal other Moonrunners from silver injury.
Clans are a small group (usually 10 to 20 mated pairs and their children) that is lead by their Luna. They take their Clan name from the original Luna's name. They own everything communally and tend to live in one large building. Clans mark their territory by marking with urine but packs that have farms/ranches also use fences.
Wild Clans: Clans that live in very remote areas and live primarily/solely by hunting and gathering. They tend to stay in their fur for their entire lives (generally only shifting to their skin for certain rituals or to interact with outsiders), live in caves or in simple shelters and rarely use tools or wear clothing (even if they are in their skin). Generally speaking they are viewed as aggressive by outsiders but they generally only fight to protect their territory. Whenever their Lunas walk the Moonpath the clan usually disperses and is absorbed by other clans.
Farming Clans: Build large farms for both animals and vegetables that forms the bulk of their diet (although they do still hunt and gather... it's more of a ceremonial thing though). They are as likely to be in their skin as their fur and are only seen naked if they had to shift back to their skin without clothing nearby. Their Luna tends to find a heir before they walk the Moonpath and on the rare occasion they don't the pack will then vote to decide what to do. Usually it's to invite a young Luna or agree to follow a nearby Luna. They stay in the same building but the now united clan is able to come and go from both properties freely. There has been the occasional clan who's followed the Luna's Mate or in very rare occasions change their government to something else (these Clans rarely lasts long though before they go back to the usual system). Wild clans call them Domesticated and members of other species sometimes call them Civilized but they aren't fond of either term.
A Luna is a Moonrunner, usually female but can be male, who has a special tie to the moon. They are the leader of their clans and their word is absolute within it. They train the young Lunas who may or may not be their heirs. They are also the lore-keepers of their people and are specially trained to remember the many stories of their kind. They are the only ones to wear silver and they carry a silver dagger as a symbol of their right to kill any wolf who breaks Clan Law. Actually using this dagger is very rare though.
Fated Mates are two people (usually male/female but can be same-gender) who are meant to be a couple. Their stories state the Moon herself ties them together. This bond is for life and cannot be broken. With that said they do separate to walk the Moon Path but believe they will be reunited in death. With one exception in all their history Mates are always both Moonrunners.
The Moon Lady: The Creator and central god of their faith. They believe that she is the one who gave them the ability to shapeshift. Conversely, silver, the only metal that can cause lasting harm is said to be Her metal, given to the Lunas to keep their clans under their control. Some clans say she has a mate but some say she doesn't. Those who do tend to say he's the sun (and they tend to view him as an almost demonic figure) but there are other stories.
The Lady of the Forests and Fields: Their mother nature goddess. She's the Goddess called upon during childbirth and whenever they are gathering plant matter. The first fruits of the year are always offered to Her.
The Lord of the Hunt: Their hunt and death god. He's the one they offer the hearts of their prey to (this prey must be wild and properly hunted so Farming clans make it a point to hunt ceremonially to make these offerings). He's the one who judges dead Moonrunners and guides those who were honorable in life to the fields of the Moon, where they run among the stars until they are ready to be reborn. The dishonorable he makes into a member of His pack where they help him hunt demons for eternity or until they are ready to be reborn (depends on the clan). For those clans who believe he keeps the dishonorable forever they believe he breaks the bond between them and their mate. If their mate was honorable they are given a new mate by the Moon Lady.
It should be noted sometimes the Lady and Lord are siblings but sometimes they are mates and sometimes both. If they are mates then they are the ones who created the physical universe, if not their mother did and set them to rule it.
They were one of the groups who migrated into Haven from earth. Notably however they chose to fight alongside the natives against the other migrants (the only group who did). While not exactly happy being under the Compact, they are also the only group that didn't add their magic to curse of the Star Dancers. Since then they've been pretty peaceful (most fighting is because they went after someone's domestic stock). It is unknown exactly how many of them there are or even how many clans because some of them live in very remote areas. The nearer to other species they live, the more likely they are to have farms and/or ranches and spend time in their skin rather than fur.