Variations: Enfield; Alphyn; Water-dog, Sea-dog


The Onchú, “Water-dog”, is a peculiar Irish creature with a long history of phonetic transformation. It is better known as the Enfield or Alphyn.

Of the three variants it is the enfield that has the most defined morphotype. It has the head of a fox, the chest of a greyhound, the talons of an eagle, the body of a lion, and the hindlegs and tail of a wolf. A more simple description gives it the head of a fox, the breast and forelegs of an eagle, and the hindquarters of a wolf, combining the cunning of the first, the honor of the second, and the ferocity of the third. There may be a mane and a lion’s tail. Enfields are rarely used in heraldry, most notably appearing in green as the crest of the O’Kelly family of Ireland. This is traditionally attributed to an incident when Tadhg Mór Ua Ceallaigh, the ancestor of the O’Kellys of Hy-Many, fell in battle against the Danes at Clontarf. An enfield or dog-like creature emerged from the sea and protected Tadhg Mor’s body until it was recovered.

As for the alphyn, it vaguely resembles a tiger, sometimes with the same clawed forelimbs as the enfield. It shares its name with the term alphyn or alfin for the chess bishop, itself derived from al-fil, “the elephant”, but this is coincidental. Elephants were well-known in bestiaries long before the decidedly unproboscidean alphyn, which appears at the end of the fifteenth century.

The word onchú is more ancient than enfield or alphyn, and is probably derived from , “hound”, and on, “water” (as in onfais, “plunging”, and onfaisech, “diver”). It is synonymous with doburchú, the otter (literally “water dog”). Therefore the onchú can be inferred to be a dog or dog-like animal that lives at least partly in water. Onchú also is used to mean “banner”, or “standard”, suggesting that the use of the onchú on battle-standards was common enough that the name was transferred to the item – and that its use preceded the battle of Clontarf.

The confusion only increases with the pluralization of onchú to give onchoin or onchainn. Onchainn in turn became onfainn following the trend of ch conversion (e.g. Dunphy from Donnchaidh). Williams traces phonetic vagaries and lists a sequence of alterations: onfainn to anchainn to anfainn to anfaill to anfild to enfild. Anfaill also gave rise to the less-successful alternative name of alphyn. Further assimilation with the heraldic sea-dog gave the onchú/enfield/alphyn a mane and clawed, bird-like forelegs.

Since then onchú has been used as a term for a large water beast. It is wild, fearsome, valorous, heroic, with reptilian and venomous qualities (probably the origin of its green color). The onchú that lived between Loch Con and Loch Cuilinn killed nine men. Muiredach pursued it into the water and slew it, earning the title of Cú Choingelt, “Hound of the Pasturage”.

Williams proposes the adoption of onchú as the official Gaelic term for the animal. Enfield remains an acceptable English version.


Barber, R. and Riches, A. (1971) A Dictionary of Fabulous Beasts. The Boydell Press, Ipswich.

Cooke, T. L. (1859) Proceedings, November Meeting. The Journal of the Kilkenny and South-East of Ireland Archaeological Society, v. 2. McGlashan and Gill, Dublin.

Vinycomb, J. (1906) Fictitious and Symbolic Creatures in Art, with Special Reference to their Use in British Heraldry. Chapman and Hall, London.

Williams, N. J. A. (1989) Of Beasts and Banners: The Origin of the Heraldic Enfield. The Journal of the Royal Society of Antiquaries of Ireland, v. 119, pp. 62-78.