Irish Mythological Creatures: 23 Fairies And Monsters

The best-known Irish mythological creatures are the aos sí (the fairy people), the banshee, the púca, the Dullahan, the leprechaun, the merrow and the changeling. The medieval sagas add the Fomorians, Balor of the Evil Eye and the Morrígan. Ireland also has water monsters like the dobhar-chú and each uisce, and two “ancient” vampires that are surprisingly modern.

Ireland is a small island with a very crowded otherworld. Some of its creatures are over a thousand years old. A few are much younger than you’d think.

Here are 23 Irish folklore creatures, grouped by type, with the Irish name, a plain way to say it and what the old sources say.

Samhain (say SOW-in), the old Irish feast on 1 November, was when the fairy mounds were said to open. For the background, see how the Irish invented Halloween.

Jump to a section:

Old myth, folk belief or modern invention?
Types of Irish fairies: the fairy folk
Fairy tricksters
Death omens and the dead
Shape-shifters and water creatures
Irish mythology monsters, giants and a war goddess
Irish mythological creatures FAQ
More Irish Halloween reading

Old myth, folk belief or modern invention?

Irish creatures come from three places. The oldest live in medieval sagas, written down by monks from roughly the 8th to the 12th century. The Fomorians, Balor and the Morrígan belong here.

Next comes folk belief. Thomas Crofton Croker (1825), Lady Wilde (1887) and W. B. Yeats (1888 and 1892) wrote down what country people told them. From 1937 to 1939 the Schools’ Collection had Irish children record family lore. It’s free at duchas.ie.

Last comes modern invention: “ancient” details that first appear in 1990s books or online. I’ll flag those as we go.

Types of Irish fairies: the fairy folk

Yeats split fairies into trooping and solitary kinds. The solitary sort, he wrote, are “nearly all gloomy and terrible in some way”.

Aos sí, the fairy people (say “eess SHEE”)

Aos sí means “people of the fairy mounds”. These are the trooping fairies, said to live inside hills and ringforts. A ringfort, or fairy fort, is a circular earth bank left by an early medieval farmstead.

Yeats recorded “the gentry” and the daoine maithe, “the good people”, polite names so as not to offend them. Antiquarians saw them as the old gods, the Tuatha Dé Danann, shrunk down.

Their Halloween link is old. In the Old Irish tale The Adventures of Nera, a woman tells Nera that the fairy mounds of Ireland “are always opened about Halloween”. William Allingham’s poem The Fairies is their best-known portrait.

Leannán sí, the fairy lover (say “LAN-awn SHEE”)

The leannán sí (often written leanan sídhe) is a fairy or phantom lover. Ó Dónaill also gives “baleful influence” and, less romantically, “a sickly complaining person”.

The famous version is Yeats’s. In 1892 he described a fairy mistress who inspires poets and “lives on their life”, so her lovers waste away and die young. He called her “the Gaelic muse” and “this malignant fairy”.

Lady Wilde (1887) saw her differently, as “the spirit of life” that inspires poets. So the deadly muse owes a lot to Yeats. Poets do like to think they’re doomed.

Gancanagh, the love-talker (say “GAN-kaw-nukh”)

The gancanagh (Irish geancánach) is a small fairy of the leprechaun type with one hobby: romance. Yeats quotes the Louth writer O’Kearney, who says he always has a dudeen, a short clay pipe, in his mouth. He turns up in lonely valleys and courts milkmaids.

O’Kearney adds that a man who ruined himself chasing women “was said to have met a gean-cánach”. A handy excuse, that.

Online you’ll read that his skin gives off a toxin that makes women addicted. I can find no old source for it. Oddly, Ó Dónaill glosses geancánach as “fairy cobbler”.

Changeling, the síofra (say “SHEE-fruh”)

A changeling was a fairy said to be left in place of a stolen baby, or sometimes a young wife. Ó Dónaill glosses síofra as “elf-child; changeling”.

The classic tale is Croker’s The Brewery of Egg-shells (1825). Mrs Sullivan boils eggshells in front of her sickly child. It sits up and says it is “fifteen hundred years in the world” and never saw the like. Her own child comes back.

The belief did real harm. In 1895 Bridget Cleary of Ballyvadlea, Co. Tipperary, was burned to death by her husband, who claimed she was a changeling. Angela Bourke’s 1999 book tells her story. There’s more in our changelings guide and Yeats’s poem The Stolen Child.

Fairy tricksters

These three are solitary fairies in Yeats’s scheme. I wouldn’t lend them money.

Leprechaun, the leipreachán (say “LEP-rukh-awn”)

The leprechaun’s oldest ancestor is the luchorpán of the Old Irish saga of Fergus mac Léti, from around the 8th century. Little beings drag the sleeping King Fergus toward the sea. Caught, they buy their freedom with a gift: the power to go under water.

The Dictionary of the Irish Language calls the luchorpán a small supernatural creature, “later anglicised as leprechaun”. It even floats a Latin origin, lupercus. Yeats passed on a folk derivation, leith bhrógan, “one-shoemaker”, but scholars favour the older word.

And he didn’t wear green. McAnally, quoted by Yeats in 1892, gives him “a red coat with seven buttons in each row”. The green suit came later. More in leprechauns in Irish folklore and 20 things you didn’t know about leprechauns.

Clurichaun, the clúracán (say “KLOOR-uh-kawn”)

The clurichaun is the leprechaun’s disreputable cousin. Some writers, Yeats noted, thought him the leprechaun himself, off “on the spree” after work.

His hobbies, says Yeats, were robbing wine cellars and riding sheep and sheepdogs all night. In Croker’s “The Haunted Cellar” (1825), a cluricaune called Naggeneen drinks his way through the port of Mr Mac Carthy of Ballinacarthy.

Yeats said the clurichaun was “almost unknown in Connaught and the north”. Munster, it seems, had the better cellars.

Far darrig, the fear dearg (say “far DYAR-ug”)

Fear dearg means “red man”. Yeats called him “the practical joker of the other world”, and said he wears a red cap and coat. His jokes, according to Yeats, often ran to the gruesome.

Croker has a gentler story, The Lucky Guest. In Keightley’s retelling, a little old man in a red sugar-loaf hat and scarlet coat knocks at a cabin on a stormy night. His visits bring the family good luck.

Let the strange red man in, then. Within reason.

Death omens and the dead

Now for Halloween proper, though the two Irish vampires here are younger than the internet claims.

Banshee, the bean sí (say “ban SHEE”)

Bean sí means “fairy woman”. According to tradition she follows certain old Irish families and cries or keens before a death. Keening is the old Irish lament for the dead.

The standard study is Patricia Lysaght’s The Banshee (1986). She found regional names too, like “the Bow” in Wexford and Carlow, from badhbh. Ó Dónaill glosses badhbh as war-goddess and carrion crow, and even lists badhbh chaointe, “banshee”.

You’ll read that only five families have a banshee. The folk records name many more. More in our guide to the banshee in Irish folklore.

Dullahan (say “DULL-a-hawn”)

The Dullahan is Ireland’s headless horseman. The earliest printed tales are in Croker’s Fairy Legends (1828), mostly set in Co. Cork, my own county.

Yeats wrote “This is a most gruesome thing.” He described the cóiste bodhar (say KOH-shtyeh BOW-er), a black coach drawn by headless horses. If it stops at your door and you open it, a basin of blood is thrown in your face. It is an omen of death.

The word’s origin is uncertain, though Croker’s informant Edward O’Reilly said it meant “a dark sullen person”. Ó Dónaill gives dúlachán only as “lake trout”. I can find neither the fear of gold nor the whip made of a human spine in Croker, Lady Wilde or Yeats. See our Dullahan guide.

The sluagh, the slua sí (say “SLOO-uh SHEE”)

Slua means a host. Ó Dónaill gives “an slua sí, the fairy host” and “slua na marbh”, the host of the dead.

The scary version, the restless dead flying in flocks, is mainly Scottish. Alexander Carmichael heard it in Uist and Barra and printed it in 1900. The dead flew “like the starlings”, he wrote, and came from the west. So people shut the west door and windows when someone was dying.

Most lists call that Irish. It’s Hebridean.

Fear gorta, the man of hunger (say “far GUR-tuh”)

Yeats describes the fear gorta as “an emaciated fairy that goes through the land in famine time, begging and bringing good luck to the giver”. That’s the whole creature.

Online lists turn him into a zombie corpse. I can find no old source for that.

Don’t confuse him with féar gortach, “hungry grass”. Lady Wilde (1887) describes cursed ground that brings sudden, weakening hunger on anyone who steps on it. Ó Dónaill still has “Tháinig féar gortach orm”, “I was overcome with hunger”.

Abhartach (say “AV-ar-tukh”)

The first detailed account in print of this “Irish vampire” is P. W. Joyce’s Irish Names of Places (1869). Joyce heard it from a local. He explains Slaghtaverty in Co. Derry as Leacht Abhartaigh, “the monument of the dwarf”.

In Joyce, the dwarf is “a magician, and a dreadful tyrant”. A neighbouring chieftain kills him, but he comes back. After a second return, a druid advises killing him again and burying him head downwards, which works. Joyce’s 1871 edition adds that “some say” Finn Mac Cumhail was the killer.

Joyce says nothing about blood. The blood-drinking first appears in print in 1997, in Peter Haining and Peter Tremayne’s The Un-Dead. Bob Curran popularised it in History Ireland in 2000, where he suggested the legend inspired Dracula. More in our Irish vampire guide.

Dearg-due (say “DYAR-ug DOO”)

The popular story has a Waterford girl, forced to marry a cruel man, who dies by her own hand and rises to drink men’s blood.

The oldest printed trace is two sentences in Dudley Wright’s Vampires and Vampirism (1914). A “beautiful female vampire” lies under a graveyard near “Strongbow’s Tower” in Waterford. She has no name.

In 1929 Montague Summers wrote that Waterford never had a “Strongbow’s Tower”. On the same page he said the Irish vampire was “generally known as Dearg-dul”, but gave no source. Anthony Masters respelled it Dearg-due in 1972, and by 1980 Peter Haining had pinned the name on the Waterford vampire. The forced-marriage story came later still.

“Due” isn’t Irish spelling. Summers glossed dearg-dul as “red blood sucker”, and Ó Dónaill does have diúl, “suck”.

Shape-shifters and water creatures

Ireland is wet, so plenty of its creatures live in water. Several are shared with Scotland, which is why they turn up on lists of Celtic mythical creatures.

Púca (say “POO-kuh”)

Ó Dónaill glosses púca as “hobgoblin, pooka, puck”. Yeats called it “essentially an animal spirit”. It appears as a horse, ass, bull, goat or eagle, and loves taking a rider on a wild night gallop.

The púca owns Halloween. Yeats wrote that November Day is sacred to the Pooka, and that after November Eve “the blackberries are no longer wholesome”. Ó Dónaill even has “púca na sméar”, the fruit-destroying pooka, herald of winter.

If your granny wouldn’t let you pick blackberries after Halloween, now you know why. Our full púca guide has more.

Cat sí (say “kat SHEE”)

The fairy cat is mainly Scottish Highland lore, spelled cat-sìth. The earliest full description is J. G. Campbell’s Superstitions of the Highlands and Islands of Scotland (1900). He describes black cats “as large as dogs”, with a white spot on the breast.

Many, he adds, thought they were witches in disguise. The soul-stealing and the Samhain saucer of milk come from later retellings.

Ó Dónaill has no entry for cat sí, so treat it as a Scottish cousin. See our Cat Sìth guide.

Merrow, the murúch (say “MUR-ookh”)

Ó Dónaill glosses murúch as “mermaid”. Yeats says fishermen hated to see one, as a merrow meant coming gales. He adds that she wears a red feathered cap, the cohullen druith, and can’t go back under the waves if it’s stolen.

Croker’s The Lady of Gollerus, set at Smerwick in Co. Kerry, is the classic merrow-bride tale. A man hides her cap and marries her. She leaves the day she finds it.

One famous merrow story, The Soul Cages, first appeared in Croker’s book in 1828. Thomas Keightley later admitted he built it from a German legend, calling the rest “our own pure invention”. He afterwards heard a version on the Cork and Wicklow coasts.

Selkie, the seal folk (Irish rón, a seal, say “ROHN”)

Selkies are seals who can shed their skin and walk as people. The tradition is strongest in Orkney and Shetland, in the far north of Scotland.

Ireland has seal stories too. The Conneely family of Connemara are often said to descend from seals. David Thomson wrote about the belief in The People of the Sea (1954).

More in selkie mythology and the ballad of The Great Silkie of Sule Skerry.

Each uisce, the water horse (say “akh ISH-kuh”)

Each uisce means “water horse”, and Ó Dónaill lists it under mythology. It’s a cousin of the Scottish kelpie.

Yeats says water horses used to “come out of the water to gallop on the sands”, and could be caught and bridled. But if one caught sight of the water again, it would plunge in with its rider and “tear him to pieces at the bottom”.

In 1846 the historian James Hardiman noted that in the west, the lake beast was “generally called Each Uisge”. Moral: don’t ride strange horses near water.

Dobhar-chú, the water hound (say “DOW-er-khoo”)

Dobhar is an old word for water and cú means hound. In modern Irish, dobharchú means otter.

In 1684 Roderic O’Flaherty described an “Irish crocodil” in Lough Mask, though his book was only printed in 1846. It grabbed a man by the elbow, then sank its teeth into his head and dragged him into the water. He stabbed it with his pocket knife and it swam off.

It was the size of a greyhound, with black, slimy, hairless skin. “They call it Dovarchu,” he wrote.

At Conwal graveyard in Glenade, Co. Leitrim, a carved slab marks Grace Connolly, reputedly killed by one while washing clothes. One 1930s Schools’ Collection account describes “half a dog and half a fish with a spear stuck in his side”. It gives the year only as “17”, the rest left blank. Another Schools’ Collection account says the stone is dated 1722.

The werewolves of Ossory (say “OSS-uh-ree”)

Gerald of Wales tells this one in his Topography of Ireland (about 1188). Ossory was an old kingdom, roughly today’s Co. Kilkenny.

Around 1182, a priest travelling from Ulster to Meath meets a talking wolf from Ossory. St Natalis, an abbot, had cursed the people there. Every seven years a man and a woman must live as wolves, far from home, for seven years.

This wolf’s mate is dying. He peels back her wolfskin to show the priest an old woman underneath.

Irish mythology monsters, giants and a war goddess

These come from sagas and saints’ legends, not fireside belief. See also our guide to Celtic gods and goddesses.

Oilliphéist, the serpent monster (say “UL-ih-faysht”)

Ó Dónaill glosses ollphéist as “serpent, (serpentine) monster”. Yeats listed the “Pastha”, the lake dragon, as “a guardian of hidden treasure”.

The best-known one is the Caoránach of Lough Derg in Co. Donegal. Local tradition says St Patrick defeated her in the lake, and some tellings say her blood turned it red.

Ireland has no snakes, as every child is told. According to these stories, they’re all at the bottom of lakes.

The Fomorians and Balor, the Fomhóraigh (say “FOH-war-ee”)

Ó Dónaill glosses fomhórach as “Fomorian; pirate; giant”. In the Book of Invasions they oppress Ireland’s early settlers from Tory Island. One medieval text lists them beside goat-headed monsters and luchorpáin as descendants of Noah’s son Ham. Another gives them one hand and one foot.

Their champion is Balor (say BAL-ur). Cath Maige Tuired (Stokes’s 1891 translation) says: “Four men used to lift up the lid” of his evil eye. Balor’s grandson Lugh drives the eye through his head with a sling-stone. For the other old races, see the Fir Bolg.

The Morrígan (say “MOR-ee-gan”)

The Morrígan is a war goddess, not a monster, though she’s hard to tell apart on a bad day. Her name is usually read as “phantom queen” or “great queen”. She often appears with Badb and Macha as a trio.

In Cath Maige Tuired, the Dagda meets her at Samhain, washing in the River Unshin in Co. Sligo. She stands with one foot on each bank. She promises to destroy the Fomorian king.

In the Táin she attacks Cú Chulainn as an eel, a wolf and a heifer. In popular retellings of his death, a crow lands on his shoulder.

Irish mythological creatures FAQ

What is the scariest creature in Irish mythology?

For my money, the Dullahan and his death coach. Yeats called him “a most gruesome thing”. Balor of the Evil Eye, whose eye was opened only on a battlefield, is a close second.

Is there an Irish vampire?

Not an old one. Abhartach is a Derry legend first printed in 1869, about a dwarf who rose from his grave. The blood-drinking first appears in print in 1997. The Dearg-due’s backstory is later still.

What are Irish fairies called, and what types are there?

In Irish they are the aos sí, “people of the fairy mounds”, or the daoine maithe, “the good people”. Yeats split them into trooping fairies, who live together in hills and forts, and solitary ones like the leprechaun and far darrig.

Which Irish creatures are linked to Halloween?

The aos sí, whose mounds were said to open at Halloween, and the púca, who spoils the blackberries after it. The Morrígan meets the Dagda at Samhain.