The bat, the toad, the hedgehog, and the pig are symbols of evil or gluttony in Western art.
The bat is generally known as a symbol for the night. Furthermore, in the West it is a symbol of evil and is associated with vampires. But in China it symbolizes good luck and longevity. Bats were considered by the early Christians to be “birds of the Devil” because of their association with darkness and their similarity to rats. Thus they were known as a symbol of fear with an awareness of the powers of darkness and chaos. Albrecht Dürer produced an important print featuring a bat. Produced in 1514, “Melencolia I” is probably his most intriguing engraving: a masterpiece with a complex composition and interpretation that has always intrigued scholars. A bat with open wings bears the title of the work (the first state of melancholy).
Toads, similar to snakes, are characterized as unclean. Furthermore, because toads can eject poison that irritates skin and eyes, they are typically a symbol of death. In mythology toads are often viewed as demons and are associated with the Devil. Toads are also found in the Bible as a punishment as in the plagues of Egypt (Exodus 7:27-29; 8:1-10). In the fantastic painting of Hieronymus Bosch “The Garden of Earthly Delights,” on its right panel, there is a figure of a woman with a toad encircling her breast and an ass for a partner. The woman is Superbia (Latin for “Pride”) and the toad is generally believed to symbolize the sin of debauchery.
Because in legend the hedgehog supposedly rolls on top of fallen fruit to gather it on its spines and walk off with it, saving more than it needs to sustain itself, it became a symbol of gluttony. Today, due to its quiet, discreet, and dignified nature, the hedgehog embodies gentleness. The hedgehog is prickly when under attack or mistrustful, but gentle and friendly to known or trusted people.
In the art of Christianity, the pig is considered an unclean symbol of lust, greed, and gluttony.
Saint Anthony the Great, also known as St. Anthony Abbott (251–356), retreated from wealth to live as a hermit in the desert of Egypt. He resisted many temptations sent by the devil until his death at the age of 105. His great holiness attracted others who came to live near him, and he is often considered the father of Christian monasticism. Usually carrying a staff and pictured as an old man, he is associated with a pig which represents his victory over the demon of gluttony. A pig can be seen in the background of the painting "The Visitation with Saint Nicholas and Saint Anthony Abbot "(1490), seen here in this detail depicting Saint Anthony, by the Florentine painter Piero di Cosimo (1462-1521).
Today pigs may be considered to be symbols of good fortune, thrift, and savings. Children are traditionally given piggy banks to encourage them to save.
Bailey, Colin J. “The Art Quiz Book: 2000+ Questions on Painters and Paintings.” Station Press: Scotland, 1995