A Guide To 31 Of The Scariest Celtic And Irish Mythological Creatures

Irish mythological creatures
Photo left: R. de Moraine (wikicommons). Right: Fer Gregory

One of the most common questions we get in relation to Irish mythology revolves around Irish Mythological Creatures (or Celtic mythological creatures).

Now, if you’ve spent any time reading about Irish folklore, you’ll know that there are quite a few Irish mythological creatures out there, and that they, ehm, vary in their type.

Some Irish mythology creatures, like the Pooka, have a nice, fun tale tied to them while others, like the Abhartach, are nothing short of terrifying!

In the guide below, you’ll discover 32 Irish mythological creatures along with some snappy information on each one. Make sure to see our guide to Celtic Gods and Goddesses, after!

Section 1: Terrifying Irish Mythological Creatures / Irish Monsters

The first section of our guide is dedicated to Celtic mythological creatures that veer towards the ‘terrifying’ side of things.

This is where you’ll find the faeries that you wouldn’t want to run into a dark alley and the Irish vampire that you wouldn’t want to run into anywhere!

1. The Abhartach (The Irish Vampire)

The Abhartach
Irish mythological creatures: Photo by Wilqkuku (Shutterstock)

First up is arguably the scariest of the many Irish mythology creatures / Irish monsters – the Abhartach. Now, it’s widely known that Bram Stoker’s Dracula has close ties to Ireland.

The author was, of course, born in Dublin. However, it’s not Dracula that we’re referring to, here. The tale of the Abhartach is one that’s hard to debunk, and many believe that it’s real.

In this guide, we tell the story of this Celtic mythological creature, and offer insight into where in Ireland it roamed (and where it’s now buried).

2. Balor of the Evil Eye

Balor of the Evil Eye
Photo by Shvaygert Ekaterina/shutterstock

The leader of supernatural creatures called the Fomorians, Balor of the Evil Eye, one of many Irish demons, was, unsurprisingly enough, a giant with a large eye.

While he was spying on his father’s druids, the noisome vapours of a spell entered his eye. The eye became swollen and granted him the power of death.

3. The Banshee

the banshee
Photo by Valery Sidelnykov (Shutterstock)

The Banshee is one of the better-known of the many Irish mythological creatures / Irish monsters, mainly due to the popularity of storytelling in Irish culture.

A female spirit from Irish mythology, the Banshee can appear in many forms. She can be an old woman with frightening eyes, a pale lady in a white dress, or a beautiful woman wearing a shroud.

Regardless of how she looks, it’s her wail that sends shivers up the spine of many, as it signals impending doom. Read more about the Banshee here.

4. The Oilliphéist

Oilliphéist celtic creature
Photo by 80’s Child/shutterstocj

Although you’ll often hear the Oilliphéist described as a Celtic monster, it was said to take on the appearance of a dragon.

The Oilliphéist used to inhabit the dark, murky waters of many lakes and rivers across Ireland and many Irish warriors ended up fighting these Celtic folklore creatures.

5. The Dearg Due (one of the lesser-known Irish mythological creatures)

Dearg Due
Photo left: R. de Moraine, Public domain, via Wikimedia Commons. Right: Olga Vasileva

Ah, the Dearg Due. She stands in the shadows of the better-known Abhartach, but she’s none the less terrifying, in our opinion.

The Dearg Due is one of several Irish mythical creatures / Irish monsters whose characteristics resemble that of a vampire.

Her name translates to “red bloodsucker” and, according to legend, she’s a cunning vampire who seduces men and drains them of their blood.

6. The Dullahan

The Dullahan creature
Photo by Mzorin/shutterstock.com

People tend to view faeries as happy little Irish mythological creatures that possess a variety of magical powers.

Our next creature, the Dullahan, is a faerie that you’d struggle to describe as ‘happy’, as it takes the form of a headless rider on a black horse.

According to legend, this Irish folklore creature uses the spine of a human as a whip. The Dullahan can also foreshadow deaths. If he calls out your name, you will immediately drop dead.

7. Fomorians

the Fomorians
The Fomorians by John Duncan (1912)

Now, just to be clear – the Fomorians aren’t exactly dangerous Celtic mythological creatures, they’re more terrifying in appearance.

A race of supernatural giants, Fomorians are often described as hideous-looking monsters who came from the sea/underworld. 

Irish tales tell many tales of these creatures who were one of the earliest races to settle in Ireland, along with the mighty Tuatha Dé Danann.

8. Bánánach (Irish Demons)

one of the creepiest celtic monsters
Photo by Raggedstone/shutterstock.com

Annnnd we’re back to creepy Celtic monsters again, next, with the Bánánach. In Irish folklore, Bánánach are a supernatural race that were known to haunt battlefields.

These airborne shrieking demons may have had a goat-like appearance and were associated with violence and death.

9. The Sluagh

The Sluagh irish mythological creature
Photo by Fer Gregory/shutterstock.com

Sluaghs were one of a handful of Irish mythical creatures that well and truly creeped me out as a child, after hearing stories about them from friends.

These Celtic monsters were restless spirits that were said to be neither welcome in hell or heaven, so they were left to roam the lands.

According to legend, the Sluaghs were angry about their fate and would snatch the soul of anyone with who they cross paths.

10. Ellén Trechend

Ellén Trechend irish mythology
Photo by Sofya Dushkina/shutterstock.com

Ellén Trechend was a true Celtic monster. In fact, it was a 3-headed Celtic monster! Now, like many Irish mythological creatures, the form of Ellén Trechend changes depending on the tale.

Some stories represent the creature with the form of a vulture, while others describe it as a fire-breathing dragon.

Ellén Trechend is known to emerge from a cave and embark on a rampage of destruction in a tale called the Cath Maige Mucrama.

Section 2: Harmless Celtic Mythological Creatures

Right, it’s time for some less creepy Celtic Mythological Creatures. In section two, we tackle the less harmful Celtic creatures.

It’s here that you’ll find the likes of the Leprechaun and, my personal favourite, the mischievous shape-shifter known as the Pooka!

1. The Leprechaun

the Leprechaun
Photo by hand draw/shutterstock.com

The Leprechaun is arguably the best known of the many Celtic creatures – mainly due to its association with Ireland and the quirky tale attached to it.

In Irish folklore, these elf-like creatures are tricksters who cannot be trusted and will deceive you whenever possible.

Contrary to popular belief, the Leprechaun has nothing to do with the term the Luck of the Irish. This term actually has offensive origins. 

2. The Pooka

the pooka aka the puca
Photo by Kamaronsky (Shutterstock)

The Pooka (or Puca) is one of several Irish mythological creatures that doesn’t get half the attention that it deserves.

This mischievous little fella is said to bring either good or bad fortune and it can appear in various animal forms, though he always wears a dark coat.

The Pooka has the power of human speech and it loves to confuse and terrify people. Read more in our guide here.

If you’re looking for stories about Irish mythical creatures to tell your kids, then this one is more than suitable!

3. The Merrow

the Merrow irish folklore creature
Photo by Koryaba/shutterstock.com

This Celtic mythological creature is best described as a mermaid in appearance, however, this is where the similarities.

Like many Celtic creatures, the Merrow has incredible powers, and it is able to reside on land or at the depths of the ocean.

The merrow is said to be half fish (from the waist down) and half beautiful woman (from the waist up) and, according to legend, is friendly and modest.

4. Fear Gorta

Fear Gorta irish folklore creature
Photo by Joe MoJo/shutterstock.com

The Fear Gorta is one of a number of Celtic folklore creatures that emerged during the time of the famine in Ireland.

The Fear Gorta is a Celtic creature that takes the form of a tired and weather beating man, who begs for food.

In exchange, the Fear Gorta (also often referred to as “man of hunger”) offers fortunes to those that offer assistance or kindness. 

5. The Clurichaun

Clurichaun creature
Photo by Allyur1950/shutterstock.com

The Clurichaun is a strange one. It’s like the Pooka, to an extent, in that it plays jokes on people, but that’s where the similarities end.

In a nutshell, this is one of a number of Irish folklore creatures that closely resemble people that you’ll find in towns and villages across the world.

The Clurichaun takes on the appearance of an old man that’s too fond of alcohol and that likes to play tricks on people…

6. The Far Darrig

Far Darrig
Photo by abeadev/shutterstock.com

A supernatural being with long snouts and skinny tails, the Far Darrig are actually closely related to leprechauns in Irish mythology.

These small faeries usually wear red caps and coats and, similar to the Clurichaun, love to play practical jokes on humans.

Section 3: Irish Mythology Creatures That Were Fierce Warriors

If you read our guide to Irish Mythology, you’ll know that there’s plenty of Irish mythological creatures that were known to be fierce in battle.

In the section below, you’ll find Celtic creatures that have graced many a battlefield and that are known to be skilled warriors.

1. Abcán

Tuatha Dé Danann
Photo left: zef art Right: John Duncan (1911)

The first of our Celtic mythology creatures is the mighty Abcán. A dwarf poet and a musician, Abcán was a member of the fearless Tuatha Dé Danann.

He used to own a cool bronze boat with a tin sail. In one story, Abcan gets captured by the great Irish warrior Cú Chulainn.

How did he free himself? He whipped out an instrument and played soothing music until Cú Chulainn fell asleep.

2. Aos Sí

aos si irish mythological creature
Photo by Raggedstone/shutterstock

Aos Sí translates to “people of the mound”. These Celtic folklore creatures can be very protective and can appear in a form of either beautiful or grotesque creatures.

According to legend, if a human did something to offend them, they wouldn’t hesitate in seeking painful revenge.

3. Aibell

Aibell Goddess
Photo by Ververidis Vasilis/shutterstock.com

Aibell is one of a number of Irish mythology creatures that uses music to defeat their enemies. A guardian of the Dál gCais (an Irish clan), Aibell is the Fairy Queen of Thomond.

She lived on Craig Liath and played a magic harp. It is believed that whoever listened to her play would die rather sooner than later.

4. The Man-Wolves of Ossory

Man-Wolves of Ossory
Photo by Denis Andricic/shutterstock.com

Hmm. In hindsight, maybe the Man-Wolves of Ossory should have been put with the Celtic monsters at the beginning…

The motif of Man-Wolves of Ossory is quite strong in Irish mythology and many old tales revolved around these tribes of wolf-men.

Ancient kings of Ireland used to seek their assistance during war times when they were going up against a fierce opponent.

5. The Fairy Queen

the fairy creatures in irish mythology
Photo by Khomenko Maryna/shutterstock.com

You can’t talk about Irish mythological creatures without mentioning the fairies. And you can’t mention the fairies without first introducing the fairy queen. 

The ruler of all fairies, the Fairy Queen is one of the most famous Celtic creatures. Often named Titanian or Mab, she is often described as both seductive and beautiful.

6. The Fairies

irish faires
Photo by andreiuc88/shutterstock.com

Fairies are easily the best known of the many Irish folklore creatures, and they’re presences has been seen in everything from Disney movies to video games.

The faeries are a huge part of Irish folklore and are split into two categories. While Unseelie fairies have dark agendas and are known to be troublesome, Seelie fairies are helpful and happy.

More Interesting Irish Mythological Creatures

The final section of our guide to Irish mythological creatures is a bit of a mixed bag. You’ve everything from scary Celtic monsters to more gentle, magical beings, below.

As is the case with many tales from Irish folklore, the story behind some of these creatures differs, depending on who’s telling it.

1. The Cailleach

The Cailleach
Photo by Ironika/shutterstock.com

The Cailleach is one of several Irish mythical creatures that has different forms, depending on who’s telling the story.

In old Irish folklore, the Cailleach was said to be a hag that was responsible for the creation of earth. In Scottish folklore, she is said to be one with the immense ability to influence the weather.

Often referred to as the Queen of Winter, Cailleach is one of the great Celtic mythological creatures. She controlled the weather and the winds and was popular among many Irish poets.

2. The Muckie

the muckie killarney
Photo by Dotted Yeti/shutterstock.com

The Muckie was a mysterious Irish mythical creature that’s said to inhabit the Lakes of Killarney in Ireland, earning it comparisons with Scotland’s Lough Ness Monster.

Interetingly enough, back in 2003 scientists conducted a number of scans using sonar technology to understand more about the lakes fish population.

However, eerily, the sonar encountered a large solid mass, which has fuelled speculation that the lake is inhabited by one of the last remaining Celtic mythological creatures.

3. Glas Gaibhnenn

Glas Gaibhnenn cow
Photo by IvanDbajo/shutterstock.com

If you’re looking for stories about Irish mythical creatures to tell your kids, then this one is more than suitable!

In old Irish folk tales, Glas Gaibhnenn was a magical cow with green spots that could produce endless supplies of milk for its owners.

There’s no mystery why, during a time when food was scarce, stories of this Irish mythical creature were a firm favourite.

4. Failinis

Failinis folklore creature
Photo by Volodymyr Burdiak/shutterstock.com

The fearless Failinis was one of a number of Celtic mythology animals that could go toe-to-toe with the fiercest of warriors.

Failinis was a dog who fought in many battles. He was invincible and could destroy any wild beast that he crossed paths with.

5. Gancanag

Photo by Kiselev Andrey Valerevich/shutterstock.com

The Gancanagh is another strange one, and arguably falls into the ‘Celtic monsters’ category, thanks to how his victims end up.

The Gancanagh was known to seduce both men and women with what were said to be addictive toxins that emitted a powerful, alluring scent.

However, all wasn’t as it seemed. Those that fell victim to his seductive charm ended up passing away not long after.

6. Donn Cúailnge

The Tain Bo Cuailnge
Photo via Ireland’s Content Pool

The fiercest and the largest bull in Irish mythology, Donn Cúailnge used to roam the vast forests of the Cooley Peninsula.

If you read our guide to the Cattle Raid of Cooley, one of the most famous battles in Irish Folklore, you may be familiar with this fella.

7. The Bodach

scary celtic mythological creatures
Photo by Todd Squires/shutterstock

Although similar to the boogeyman in appearance, the Bodach is one of a number of Celtic mythological creatures who, according to legend, was completely harmless.

Some tales describe the Bodach as a Celtic creature that plays tricks on kids. Others, in Scottish folklore, say he used to capture bold children (a story used to scare kids into behaving).

8. Leanan sídhe

tir na nog
Photo by Olga Vasileva (shutterstock)

Over the years, I’ve heard many different tales about Leanan sídhe. The one that appears the most describes the fairy Leanan sídhe as a beautiful woman.

The Leanan sídhe was known to spark up relationships with humans. However, not long after falling in love with Leanan sídhe, it’s lovers passed away.

The interesting bit to this story is that the lovers of Leanan sídhe were said to have lived ‘inspired’ lives. Sounds a little bit like the story of Tir Na Nog, right?!

FAQs About Irish Folklore Creatures and Celtic Monsters

Since publishing a large number of Irish folklore and Irish mythology guides, we’ve received countless emails about Irish folklore creatures.

Below, I’ve popped in the most FAQs that we’ve received. Have a question about Celtic folklore creatures that we haven’t answered? Ask away in the comments section.

What are the scariest Celtic mythological creatures?

  • The Abhartach
  • Balor of the Evil Eye
  • The Banshee
  • The Dearg Due

What are the best know Irish Celtic monsters?

  • The Bodach
  • The Man-Wolves of Ossory
  • The Sluagh
  • Bánánach

What Celtic mythology creatures are good for bedtime stories?

  • The Pooka
  • The Leprechaun
  • The Fairy Queen
  • Glas Gaibhnenn

A thirsty travel writer with a passion for weird street food, Aperol spritz, and tropical islands.


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