Brewer's: Pig

(The) was held sacred by the ancient Cretans, because Jupiter was suckled by a sow; it was immolated in the mysteries of Eleusis; was sacrificed to Hercules, to Venus, the Lares (2 syl.), and all those who sought relief from bodily ailments. The sow was sacrificed to Ceres (2 syl.), “because it taught men to turn up the earth;” and in Egypt it was slain on grand weddings on account of its fecundity.

Pig

In the forefeet of pigs is a very small hole, which may be seen when the hair has been carefully removed. The tradition is that the legion of devils entered by these apertures. There are also round it some six rings, the whole together not larger than a small spangle; they look as if burnt or branded into the skin, and the tradition is that they are the marks of the devil's claws when he entered the swine (Mark v. 11-15). (See Christian Traditions.)

Riding on a pig.

It was Jane, afterwards Duchess of Gordon, who, in 1770, undertook for a wager to ride down the High Street of Edinburgh, in broad day-light, on the back of a pig, and she won her bet.

Some men there are love not a gaping pig

(Merchant of Venice, iv. 1). Marshal d'Albert always fainted at the sight of a roast sucking pig. (See Antipathy, Cat.)

The same is said of Vaugheim, the renowned Hanoverian huntsman. Keller used to faint at the sight of smoked bacon.

Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894

Pig-back

Pietro