It is unlucky for a hare to cross your path, because witches were said to transform themselves into hares.
Nor did we meet, with nimble feet, One little fearful lepus; That certain sign, as some diyine, Of fortune bad to keep us.
Ellison: Trip to Benwell, Ix.
In the Flamborough Village and Headland, we are told, “if a fisherman on his way to the boats happens to meet a woman, parson, or hare, he will turn back, being convinced that he will have no luck that day.”
Antipathy to hares. Tycho Brahe (2 syl.) would faint at the sight of a hare; the Duc d'Epernon at the sight of a leveret; Marshal de Brééat sight of a rabbit; and Henri III., the Duke of Schomberg, and the chamberlain of the emperor Ferdinand, at the sight of a cat. (See Antipathy.)
First catch your hare. (See Catch.)
Hold with the hare and run with the hounds. To play a double and deceitful game, to be a traitor in the camp. To run with the hounds as if intent to catch the hare, but all the while being the secret friend of poor Wat. In the American war these double-dealers were called Copperheads (q.v.).
Mad as a March hare. Hares are unusually shy and wild in March, which is their rutting season. Erasmus says “Mad as a marsh hare,” and adds, “hares are wilder in marshes from the absence of hedges and cover.” (Aphorisms, p. 266; 1542.)
Melancholy as a hare (Shakespeare: 1 Henry IV., i. 2). According to mediaeval quackery, the flesh of hare was supposed to generate melancholy; and all foods imparted their own speciality.
The quaking hare, in Dryden's Hind and Panther, means the Quakers.
Among the timorous kind, the quaking hare Professed neutrality, but would not swear.
Part i. 37, 38.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894