The Amphisbaena (Amphisbaina), a Greek word from amphis, meaning "both ways", and bainein, meaning "to go". It is a serpent with two ant-eating heads, one at the top and one in the direction of the tail, sometimes depicted with the claws and legs of a bird and the pointed wings of a bat. When it advances, as need for a forward movement impels it, it leaves one end behind to serve as tail, while the other it uses as a head. Then again if it wants to move backwards, it uses the two heads in exactly the opposite manner from what it did before.

According to Greek mythology, the amphisbaena was spawned from the blood that dripped from the Gorgon Medusa's head as Perseus flew over the Libyan Desert with it in his hand. Cato's army then encountered it along with other serpents on the march. Amphisbaenae fed off of the corpses left behind. 

In ancient times, the supposedly dangerous amphisbaena had many uses in the art of folk medicine and other such remedies. It is said that expecting women wearing a live amphisbaena around their necks would have safe pregnancies; however, if one's goal is to cure ailments such as arthritis or the common cold, one should wear only its skin. By eating the meat of the amphisbaena, one could attract many lovers of the opposite sex, and slaying one during the full moon could give power to one who is pure of heart and mind. Lumberjacks suffering from cold weather on the job could nail its carcass or skin to a tree to keep warm, while in the process allowing the tree to be felled more easily.