Black Joanna of the Boyne (Siubhan Dubh na Boinne) appeared on Hallowe’en in the shape of a great black fowl, bringing luck to the house whose Vanithee (woman of the house) kept it constantly clean and neat.
The Pooka, who appeared in the shape of a horse, and whom Shakespeare has adapted as “Puck,” was a goblin who combined “horse-play” with viciousness.
The dullaghan was a churchyard demon whose head was of a movable kind, and Dr. Joyce writes: “You generally meet him with his head in his pocket, under his arm, or absent altogether; or if you have the fortune to light upon a number of dullaghans, you may see them amusing themselves by flinging their heads at one another or kicking them for footballs.”
An even more terrible churchyard demon is the beautiful phantom that waylays the widower at his wife’s very tomb and poisons him by her kiss when he has yielded to her blandishments.
Of monsters the Irish had, and still believe in, the Piast (Latin bestia), a huge dragon or serpent confined to lakes by St. Patrick till the day of judgment, but still occasionally seen in their waters.
In Fenian times the days of Finn and his companion knights, the Piast, however, roamed the country, devouring men and women and cattle in large numbers, and some of the early heroes are recorded to have been swallowed alive by them and then to have hewed their way out of their entrails.
The Merrow, or Mermaid, is also still believed in, and many Folk Tales exist describing their intermarriage with mortals.
According to Nicholas O’Kearney—“It is the general opinion of many old persons versed in native traditional lore, that, before the introduction of Christianity, all animals possessed the faculties of human reason and speech; and old story-tellers will gravely inform you that every beast could speak before the arrival of St. Patrick, but that the Saint having expelled the demons from the land by the sound of his bell, all the animals that, before that time, had possessed the power of foretelling future events, such as the Black Steed of Binn-each-labhra, the Royal Cat of Clough-magh-righ-cat (Clough), and others, became mute; and many of them fled to Egypt and other foreign countries.”
Cats are said to have been appointed to guard hidden treasures; and there are few who have not heard old Irish peasants tell about a strange meeting of cats and a violent battle fought by them in his neighbourhood. “It was believed,” adds O’Kearney, “that an evil spirit in the shape of a cat assumed command over these animals in various districts, and that when those wicked beings pleased they could compel all the cats belonging to their division to attack those of some other district. The same was said of rats; and rat-expellers, when commanding a colony of those troublesome and destructive animals to emigrate to some other place, used to address their ‘billet’ to the infernal rat supposed to hold command over the rest. In a curious pamphlet on the power of bardic compositions to charm and expel rats, lately published, Mr. Eugene Curry states that a degraded priest, who was descended from an ancient family of hereditary bards, was enabled to expel a colony of rats by the force of satire!”
Hence, of course, Shakespeare’s reference to rhyming Irish rats to death.