The coin measured 0.825 inches (21.0 mm) in diameter and a weighed 4.53593 grams.

Five early coins were minted featuring a design by Publio Morbiducci, which depict the Wolfhound's head looking back; these coins are quite valuable, estimated at several thousand euro – they remain in the hands of collectors and were never released to circulation.

[4] It has been suggested by some that the dog depicted is Master McGrath, a famous coursing greyhound raised in County Waterford.

Although the frieze of Master McGrath on the Master McGrath monument in Waterford, the only public monument in Ireland to a greyhound,[5] does bear some similarity to Metcalfe's design, there is no evidence to suggest that the animal on the coin is anything other than a wolfhound, as greyhounds are not native to Ireland.

In 1990 it was announced that the decimal penny would be redesigned to incorporate the wolfhound design,[6] but this plan was abandoned in the face of the imminent adoption of the Euro.