Picture a small town on the coast of 19th century Wales.

A family gathers around the hearth, a pan of butter toffee bubbling on the embers.

The house is decorated with branches of fragrant pine and the glow from small candles perched on the limbs of a Christmas tree lights the room.

Through a window, they see torch light coming up the path towards the cottage, accompanied by chanting.

Suddenly three hard raps at the door.

It flies open and an impossibly tall and terrifying figure looms over the family, draped in dirty white linens.

Its head is a horse's skull with glass bobbles in the eye sockets.

Ribbons tied about the skull are streaming in the wind behind it, like the hair of some horrific sea monster.

Then all at once, the group begins a merry tune, stomping and clapping in time with the grim horse's head bobbing along.

The family responds with a joyful verse of their own, and before long, the whole gaggle has made their way into the cottage, and are clanking tankards together.

Sounds like we just stepped into a scene from "A Nightmare Before Christmas," when in fact, it is a centuries old tradition from Wales called Mari Lwyd, one, it seems, of many to blend a bit of scary into their Merry Christmas.

[exciting music] I am Dr. Emily Zarka, and this is "Monstrum."

Mari Lwyd, though often used as a name to describe the monster, is actually the name of the tradition itself.

This Christmastime creature is composed of an animal skull, usually equine or bovine, attached to the top of a pole with a sat cloth or sheet draped down from the head to obscure the bearer beneath.

The skull is often elaborately decorated.

Some accounts detail glass ornaments as eyes, along with ribbons, bells and other accoutrements.

One thing is always present, however, and that is the group that travels with Mari Lwyd.

To help us gain a better understanding of this tradition, it is important to first discuss an ongoing practice in the British Isles called wassailing.

Wassailing is a Christmastime tradition dating back to the Middle Ages.

Although the specifics of the practice vary from region to region, it generally involves a group of people traveling house to house, sharing drinks, and singing with the village folk.

The tradition usually involves some form of performative bartering, like taking a drink from the wassail bowl in exchange for some type of gift.

Although wassailing is still practiced in some pockets of the British Isles, the tradition has grown and evolved over time into what many people today would call caroling.

So how does a skull fit into all of this?

We'll get into the varied opinions on the origins a bit later, but for now, let's talk logistics.

The Mari Lwyd is one of the main members of the Welsh wassailing entourage.

Along with our skeletal friend, there is usually someone who leads the group on their rounds, and is the most formally dressed.

Other characters, like the famous violent rosy-cheeked puppets, Punch and Judy, are often included as well.

This troop makes their way through the town and upon arriving at a home, will begin singing a call and response verse of sorts with the tenants within.

There are many versions of the song, both old and contemporary, but generally the song consists of the wassailers asking for permission to enter the home to feast and drink.

The people within then respond in song alike with excuses for why they can't let them in.

This carries on until the people inside can produce no further excuses, and are required to grant entry.

Mass merriment ensues.

Again, the specifics vary by region, and by time period, but generally once inside, the band partakes in holiday treats and share ale while their cranial creation would playfully chase after the children and adults eliciting screams and laughter alike.

Some elaborate Mari Lwyd creations might even feature a snapping mandible made possible through a lever or pole string contraption.

Interestingly enough, this is actually one of the British Isle's many hooded animal traditions.

There are the old horse, old ball, and old top traditions of northern England, the hooding of Kent and the broad of the Cotswolds, although these others often used a much less menacing hobby horse of sorts, and aren't always associated with Christmas.

So where exactly did this tradition come from and what does the name Mari Lwyd actually mean?

There is some disagreement on both counts.

Iorwerth Peate, a 20th century Welsh poet and scholar wrote that he believed the Mari Lwyd to be a pagan tradition that predates Christianity, much like many of the other traditions practiced around the holidays.

However, there is no historical evidence that really supports this assumption.

Nevertheless, he and others latched onto the supposed ancient origins of the custom.

Peate believe the practice was rooted in fear.

The winter holidays mark a time of darkness, cold, and death.

A skeletal horse skull does certainly evoke demise.

Although Peate originally thought that Mari must be a reference to the Virgin Mary, he later backtracked and claimed that the word is most likely a version of the word mare, as in female horse.

Other Welsh scholars of the 20th century seem to agree with him, for the most part.

Ellen Etlinger, a British art collector and folklorist believed Mari Lwyd to have connections to the Pagan holiday Samhain, evoking death.

Some folklorists suggest that it may at one point have symbolized fertility, and over time simply became associated with good luck.

There are many equine divinities in the Celtic Isles, like Rhiannon in Wales, Epona in Gal, and Maha in Ireland.

But there is very little evidence to support these theories, given the lack of references to these practices in any documents from the late medieval era.

There is, however, plenty of documentation from the 16th and 17th centuries for hobby horses throughout the region.

Costume folklore characters meant to evoke real horses, they were often used by jesters and other merrymakers during the Middle Ages.

We see references to them as early as the 1300s in a poem by a Welsh author, where he pokes some fun at the hobby horse as having a miserable pair of lathe legs, AKA really skinny wood legs.

One of the earliest known written references we have to the Mari Lwyd appears only in the 19th century where it is condemned as immoral.

Rather than being part of some ancient pagan tradition, the Mari Lwyd is likely a uniquely menacing Welsh adaptation of the British Isles' many hooded animal traditions.

The etymology of the Mari Lwyd is thus unsurprisingly similarly murky, with many scholars divided on the actual origins.

It has become consensus that the term likely means gray mare, particularly since the word llywd translates to gray in Welsh.

This would also make sense, as it parallels other hobby horse traditions throughout the region, namely in Ireland, and the Isle of Mann.

In the Celtic language Manx, it is known as the Laare Vane, which translates to white mare.

But a connection to the Virgin Mary still exists in many modern iterations of the Mari Lwyd, with very clear references to the mother of Jesus in several of the traditional songs.

But hey, it is Yule time, after all.

Despite this inclusion of Christian elements in the tradition, the Mari Lwyd was not a part of the public consciousness for most of the early 20th century because of disapproval from local Christian clergy, and general movement away from more ancient practices in an increasingly modern world.

However, by the mid-century, Mari Lwyd started creeping its way back into the light.

A 1941 poem by Vernon Watkins called "The Ballad "of the Mari Lwyd" was well-received in Welsh literary circles, as was Susan Cooper's 1977 novel "Silver on the Tree," in which Mari Lwyd appears as an undead unicorn and protector of a magic sword in the mythical sunken lands off the coast of Wales.

How that's not a movie yet is a mystery to me.

Later, the Mari Lwyd became better known outside of Wales via the tabletop role-playing game Dungeons and Dragons.

In D&D, the Mari Lwyd is an undead horse that speaks only in rhyme with a chattering jaw, and seeks entry into people's homes where it devours food and drink before needing a place to sleep, behavior clearly inspired by the original folklore.

In 2000, the artist Clive Hicks Jenkins featured Mari Lwyd in a series of drawings that personified the monster as the horrific bringer of his father's death.

This series was accompanied by poems by Catriona Urquhart titled "The Mare's Tale."

Local celebrations that included the Mari Lwyd became more and more commonplace throughout Wales as the 20th century wore on, culminating in a turn of the Millennium Jubilee in the town of Aberystwyth, wherein they rang in the new century with an elaborate procession throughout town, their top billed attraction being a massive representation of the creature, dubbed the world's largest Mari Lwyd.

Christmastime celebrations that include the tall, dark, and fearsome creation continue throughout Wales and parts of England to this day.

As regular Monstrum viewers may know, Christmastime monsters lurk in the holiday shadows of many cultures and traditions.

There's Frau Perchta, also known regionally as the Italian La Befana, the Russian babushka, or the Slavic Baba Yaga.

From Iceland, we have Gryla and her offspring, the prankster Yule Lads, not to mention our favorite murder floof, the Yule Cat, and of course, most famous, Krampus, the half goat half demon anti-Santa who punishes naughty children.

And this begs the question, why during a holiday so associated with joy and festivity do we have so many monsters, so much darkness and fear?

To answer that, we need to look at celebrations of the winter solstice.

The winter solstice has always been viewed as an important time.

The harvest seasons have now come to a close, the cold chill begins to blow in, and weather becomes increasingly less hospitable.

Traditionally without much work to do for those who would otherwise be plowing the fields, they often pass the hours by drinking and telling stories by the fire.

The Roman festival of Saturnalia occurring on or around the solstice was a holiday of opposites.

Masters would serve their slaves, the rich would garner gifts for the poor, and enslaved and free men alike would take to the streets in disguise to engage in all manner of Roman debauchery.

Yule was a Nordic and Germanic tradition, which involved feasting and celebration, but was also rife with animal sacrifice and the ceremonial smearing of blood all over the temple, and the worshipers in attendance.

Humans have always had a complicated relationship with the coming of winter.

The cold, dark depths of our chilliest season bring about a sense of wonder and also dread.

Whether we choose to approach it head on via the spooky Christmas characters of Europe, or to sugarcoat it with candy canes and gum drops, winter is a time of contemplative reflection on the small death of our world as it freezes, and sometimes the merry and the scary are a perfect marriage, as is the case with the Mari Lwyd, which despite its grim visage, is actually viewed by all participants as jolly good fun.

As long as I have you here, I want to give you a heads up that the new season of our sister show, "Fate & Fabled," is underway.

This season promises more stories of action, romance, and mystery that have been told in our weird world's folklore and mythology throughout the ages.

If you haven't checked it out already, join me and Dr. McTier for the new season of "Fate & Fabled" here on Storied.

Our Skeletal friend.

Some elaborate, Mari Lwyd.

Are you sure this is your name?

And the town of Aberystwyth?

I have to do that again.

Because it sounds like it's not a word.