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D&D 5E Mythological Figures: Fionn mac Cumhail

Mythological Figures is off to the British Isles for the man with the magic thumb: Fionn mac Cumhaill!

Mythological Figures is off to the British Isles for the man with the magic thumb: Fionn mac Cumhaill!

Fionn mac Cumhaill DnD5E banner.jpg

Fionn Mac Cumhaill (also known as Find or Finn, and also sometimes with the surnames McCool, MacCool, Cumail, or Umail) was a hunter and warrior that appears in folklore from Ireland, the Isle of Man, and Scotland, primarily but not exclusively in The Boyhood Deeds of Fionn and the Fenian Cycle narrated by his son Oisín. Fionn’s father Cumhall mac Trénmhoir ("Cumhall, son of Trénmór"; you might notice the naming convention here) was the leader of the Fianna (a warrior band made up of Clan Bascna and Clan Morna), who was distantly related through the Leinster (then the tribe of Uí Thairsig) to the Fir Bolg, and his mother Muirne Muincháem (“of the Fair/Lovely Neck”) was either the granddaughter of Nuadat (a druid serving the high-king Cathair Mór) or of Núadu (of the Tuatha Dé Danann, a deific supernatural race). Their love was refused by Muirne’s father (Tadg mac Nuadat) and saw Cumhall outlawed by the high king Conn, ending with his death at the Battle of Cnucha by the sword of Goll mac Morna who then took over the Fianna.

Already bearing Cumhall’s son, Muirne was protected from the death sentence decreed by her father thanks to Conn placing her under the protection of her sister Bodhmall and the druid’s husband Fiacal mac Conchinn. In their house she birthed her son Deimne, naming him after certainty, sureness, and also male fawn—though his name was changed to Fionn when his hair suddenly turned white at a young age. Untroubled by Conn’s declaration to protect Muirne, the Goll (sons of Morna) tried to find and kill Fionn and his brother (Tulcha mac Cumhal) so he was instead raised in secret by Bodhmall and Liath Luachra (“Grey of Luachra”) in the forest of Sliabh Bladma. By the time he was 7 Fionn could hunt and soon after began serving different kings, though as soon as he was recognized they’d send him away for fear of reprisal by his enemies.

It’s not clear if Fionn was such a good hunter that he caught and ate the Salmon of Wisdom, or if a poet he was studying under (Finnegas down in fec’s Pool of the Boyne) made the catch and after putting his burned thumb into his mouth received the cooked fish as a gift—in any event the boy gained the Thumb of Knowledge, revealing whatever he wished to know by putting his thumb in his mouth. Or sometimes the Tooth of Wisdom, or Tooth of Knowledge, and often likened to Gwion Bach and the Cauldron of Knowledge or Sigurðr Fáfnisbani and Fáfnir's heart.

With the aid of his informative appendage Fionn knew how to end the feud that had so embroiled his life. Though only 10 years old and busy marauding as an outlaw, he took the Birga spear from Fiacha mac Congha, using its magic to resist the lulling melodies of Áillen and slay the fire-breathing man of the Tuatha Dé Danann. Afterwards he gained command of the Fianna (with Goll stepping down to become his subordinate) and received the Hill of Allen as compensation for his father’s death.

Fionn had at least three wives: Gráinne (or Graine), Ailbe, and Sadhbh. The formermost was promised to him but ran away with a member of the Fianna (the famously handsome Diarmuid Ua Duibhne), and the latter was a deer. At first. Fortunately Fionn’s hounds (Bran and Sceólang) were born from a human transformed into a dog, recognizing Sadhbh was really a human cursed by the druid Fear Doirich for refusing his proposal to wed. When brought onto Fionn’s estate however she became human again, bearing him a son. Then the druid returned while Fionn was away at war, forcing her to flee and never be found again. The canines do eventually find their child Oisín as a fawn, and over time he becomes a child again and establishes his own legend with the Fianna.

This fellow is kind of a Paul Bunyan for the British Isles with accolades that include:
  • building the Giant's Causeway as stepping-stones from Ireland to Scotland to keep his feet dry.
  • creating the Isle of Man and Rockall when he scooped up a part of Ireland to throw at an enemy, missing and hitting the Irish Sea instead. Same thing for the Ailsa Craig islet.
  • sometimes depicted as a magical and kind giant (in a story where he’s disguised as a baby to scare a warrior even bigger than him, inspiring fear of how big the father of such a child must be).
  • Fionn’s feet carved out the waterways between the Calf of Man, Kitterland, and the Isle of Man, forcing his buggane (an ogre native to the Isle of Man) opponent to step into the coast to create Port Erin. As Fionn fled the fight the buggane threw one of its teeth at him, later forming the Chicken Rock (a nautical hazard).

Unlike the USA’s giant lumberjack, Fionn lives eternal and sleeps in a cave awaiting the hour of Ireland’s greatest need, a time that will be marked by three soundings from the hunting horn of the Fianna (the Dord Fiann).

Design Notes: There was some trepidation as Fionn’s history got the treatment—queued up as he was for a Mythological Figures class build—but after some deliberation the right path worked itself out. We are talking about a super duper hunter here because this is a warrior in waiting, someone of such import that they’re still alive well past the bounds of mortality. Sounds like some epic stuff so we’re going to push the throttle out to 20th level, and because we’re talking about a hunter that means ranger. Which is excellent because there’s an archetype for that class which is all about knowing things! That’s also a great solution for the oft-encountered obstacle regarding magic so long as we pick most of his spells known from the divination school. Let’s do the numbers! That bonus action Hide boosts Fion’s defensive and offensive scores pretty hard ending with a DMG score of 17.6 while the Blog of Holding comes in at a more sobering 15.666. Tricky as he may be, that damage output is awfully low so we’ll err on the lower end there with CR 15.

Fionn mac Cumhaill

Medium humanoid (human), neutral good ranger (monster slayer) 20
Armor Class 18 (breastplate, shield)
Hit Points 170 (20d10+60)
Speed 30 ft.
18 (+4)​
14 (+2)​
16 (+3)​
12 (+1)​
18 (+4)​
13 (+1)​
Saving Throws Str +10, Dex +8; Proficiency +6
Skills Animal Handling +10, Athletics +10, Perception +10, Stealth +8, Survival +10; leatherworker’s tools, vehicles (land)
Senses passive Perception 20
Languages Gaelic, Giant, Sylvan
Challenge 15 (13,000 XP)

Background: Folk Hero. Fionn is always able to rely on the hospitality of commoners to help him hide or rest provided he poses no danger in doing so, going so far as to shield him from being discovered (though not at the cost of their lives).

Favored Enemy: Fey, Giants, Humans. Fionn has advantage on Wisdom (Survival) checks to track his favored enemies, as well as on Intelligence checks to recall information about them.

Feral Senses. When Fionn attacks a creature he can’t see, his inability to see it doesn’t impose disadvantage on his attack rolls against it. Fionn is also aware of the location of any invisible creature within 30 feet of him, provided that the creature isn’t hidden from Fionn and he isn’t blinded or deafened.

Foe Slayer (1/Turn). Fionn adds +4 to the attack roll or the damage roll of an attack he makes against one of his favored enemies.

Hide in Plain Sight. Fionn can spend 1 minute creating camouflage for himself. He must have access to fresh mud, dirt, plants, soot, and other naturally occurring materials with which to create his camouflage. Once Fionn is camouflaged in this way, he can try to hide by pressing himself up against a solid surface that is at least as tall and wide as he is. Fionn gains a +10 bonus to Dexterity (Stealth) checks as long as he remains there without moving or taking actions. Once Fionn moves or takes an action or a reaction, he must camouflage himself again to gain this benefit.

Land’s Stride. Moving through nonmagical difficult terrain costs Fionn no extra movement. He can also pass through nonmagical plants without being slowed by them and without taking damage from them if they have thorns, spines, or a similar hazard. In addition, Fionn has advantage on saving throws against plants that are magically created or manipulated to impede movement, such those created by the entangle spell.

Natural Explorer: Coasts, Forests, Grasslands. When Fionn makes an Intelligence or Wisdom check related to coasts, forests, or grasslands, his proficiency bonus is doubled if he is using a skill that he’s proficient in. While traveling for an hour or more in his favored terrain, Fionn gains the following benefits:
  • Difficult terrain doesn’t slow his group’s travel.
  • Fionn’s group can’t become lost except by magical means.
  • Even when he is engaged in another activity while traveling (such as foraging, navigating, or tracking), Fionn remains alert to danger.
  • If Fionn is traveling alone, he can move stealthily at a normal pace.
  • When he forages, Fionn finds twice as much food as he normally would.
  • While tracking other creatures, Fionn also learns their exact number, their sizes, and how long ago they passed through the area.

Quarry. Fionn can use a bonus action and choose a creature within 60 feet to make his quarry. Until he finishes a short or long rest or uses this feature against a different creature, each turn his first successful weapon attack against his quarry deals an additional 1d6 damage.

Resist Quarry. Fionn gains a +1d6 bonus on ability checks to escape grapples made by his quarry and on saving throws against his quarry.

Spellcasting. Fionn is a 10th level spellcaster that uses Wisdom as his spellcasting ability (spell save DC 18; +10 to hit with spell attacks). Fionn knows the following spells prepared from the ranger’s spell list:
1st-level (4 slots): detect magic, detect poison and disease, protection from evil and good, speak with animals
2nd-level (3 slots): darkvision, find traps, locate animals or plants, locate object, pass without trace, zone of truth
3rd-level (3 slots): magic circle, speak with plants
4th-level (3 slots): locate creature, banishment
5th-level (2 slots): commune with nature, hold monster

Vanish. Fionn can use the Hide action as a bonus action on his turn. Also, he can’t be tracked by nonmagical means, unless he chooses to leave a trail.

Extra Attack. Fionn can attack twice whenever he takes the Attack action on his turn.

Mac an Luinn. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 11 (1d8+7) magical slashing damage, or 10 (1d10+5) magical slashing damage if wielded in two hands.

Spear. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 9 (1d6+6) piercing damage, or 8 (1d8+4) piercing damage if wielded in two hands.

Spear. Ranged Weapon Attack: +10 to hit, range 20/60 ft., one target. Hit: 7 (1d6+4) piercing damage.

Primeval Awareness. Fionn can expend one ranger spell slot to focus his awareness on the region around him. For 1 minute per level of the spell slot he expends, Fionn can sense whether the following types of creatures are present within 1 mile of him (or within up to 6 miles if he is in his favored terrain): aberrations, celestials, dragons, elementals, fey, fiends, and undead. This feature doesn’t reveal the creatures’ location or number.

Thumb of Knowledge (4/Long Rest). Fionn chooses a creature within 60 feet that he can see, learning its damage immunities, damage resistances, and damage vulnerabilities (unless it is under the effects of nondetection or other effect preventing divination magic).

Counter Quarry. Fionn can use his reaction to make a weapon attack targeting his quarry when he makes a saving throw against it, making the attack before rolling the saving throw. On a hit Fionn deals damage as normal and he automatically succeeds on the saving throw.

Magical Interruption (1/Short Rest). When Fionn is within 60 feet of a creature he can see casting a spell or teleporting, he can use his reaction to force it to make a DC 18 Wisdom saving throw. On a failure, the spell fails and is wasted or the creature fails to teleport (and wastes any uses of the teleporting trait, if there are any).

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Mike Myler

Mike Myler


Crown-Forester (he/him)
Nuadat is likely just a euhemerised Nuada. The Irish Cycles did that A LOT, especially when they wanted to graft the stories onto a historical narrative tying back to Troy and Babel.

Nuada is likely also the entity known as Elcmar in the Mythological Cycle (both are referred to as the spouse of Boann, who is whisked away by the Dagda without his knowledge to bear the divine son Oengus).

Nuada is known elswhere in the Celtic world as Nudd, Nodens, Lludd, Lud, and King Lear, due to confusion between Lludd and Llyr, both sea gods. The tragedy of King Lear is an adaptation of Lludd, not Llyr - Cordelia is Lludd's daughter Creiddylad. Creiddylad was beloved by both Gwythyr ap Greidawl and her own brother, Gwynn ap Nudd (this point was lost upon scholars who thought Nudd and Lludd were separate characters). Gwythyr and Gwynn would fight for her hand every May Day and Halloween, with Gwynn having her in his company in winter and Gwythyr in summer. Combine that with stories about Gwynn's Hounds of Annwfn (ghostly black Hellhounds), and his Wild Hunt (akin to that of Woden in the continent), and it's clear that Gwynn is a winter-underworld deity largely identifiable with Arawn the Otherworld King from the Mabinogion (who is fighting against Hafgan, a name that means "summer-white). Eventually, King Arthur intervenes in this fight and declares Gwythyr the "winner" and forces by military might to have both join his companions and help him hunt a giant raging boar.

But more importantly to our narrative here, Gwynn is etymologically identical to Fionn. They're the Welsh and Irish equivalents of each other. Fionn is the grandson of Nuada, and Gwynn is the son of Nudd. These are the same character mythologically.

Finally, it should be noted that the Fianna themselves are a variation of the Proto-Indo-European *Kóryos ("war party, brotherhood of arms") - an archetype that involves wandering lordless warrior bands, emulating wolves, barbarian-style rage abilities, and secret induction ceremonies. There are echoes of the *Kóryos with the Ekastaka in India (notably, these young men were inducted during the Winter Solstice - see above and associations of Gwynn with winter), the Athenian Ephebos and Spartan Krypteia, Balkan stories of werewolves and vampires (originally the same idea that diverged in later stories), the Germanic Berserkers and Vikings, Celtic naked woad-warriors such as the Pictish highlanders, the Italic "ver sacrum" ritual, the Armenian manuks, the Scythian warrior bands noted to raid on Anatolia, and the Ossetic "balc" military expeditions with their worship of the wolves & warriors god Wastyrgi during the "month of man-wolves" - again, in winter.

So what does this tell us? Fionn himself is a euhemerized deity, or demigod at the very least, associated with wolves, and likely a Barbarian mechanically, but with higher intelligence or wisdom, perhaps a warrior-poet background or a multiclass into Fighter (Battle Master). I really wouldn't choose Ranger first and foremost.
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Crown-Forester (he/him)
Wow, thanks for dropping the knowledge on us too @Marandahir . Gotta kinda disagree with your last point though, I think your "Barbarian Wolf-Guy Wisdom Warrior Poet Fighter" is about as close to a definition of the Ranger class as you are likely to get.
I guess you could go that way, especially since he would have led the Wild Hunt (Hunter Ranger?). But I do think then a dip into Barbarian to get Rage might be worthwhile. Especially if he's a God and thus can afford dips and still get a class to 20th.

Because he does more damage with one-handed melee attacks than he does using two hands, I assume he has the Dueling fighting style, though I don't see it spelled out anywhere. Also, I don't see Mac an Luinn in the writeup, but I see elsewhere that it's his sword. Maybe the references are there and I'm just not seeing them.

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