This is one of my all time favourite Medieval Bestiary depictions. I love that external spine. Wish I had one to wear.
Of the hyena. There is an animal called the hyena, which inhabits the tombs of the dead and feeds on their bodies. Its nature is that it is sometimes male, sometimes female, and it is therefore an unclean animal. Since its spine is rigid, all in one piece, it cannot turn round except by turning its body right around. Solinus recounts many marvellous things about the hyena. First, it stalks the sheepfolds of shepherds and circles their houses by night, and by listening carefully learns their speech, so that it can imitate the human voice, in order to fall on any man whom it has lured out at night. The hyena also [imitates] human vomit and devours the dogs it has enticed with faked sounds of retching. If dogs hunting the hyena accidentally touch its shadow behind, they lose their voices and cannot bark. In its search for buried bodies, the hyena digs up graves. The sons of Israel resemble the hyena. At the beginning they served the living God. Later, addicted to wealth and luxury, they worshipped idols. For this reason the prophet compared the synagogue to an unclean animal: ‘My heritage is to me as the den of a hyena.’ (see Jeremiah, 12:8) Therefore those among us who are slaves to luxury and greed, are like this brute, since they are neither men nor omen, that is, neither faithful nor faithless, but are without doubt those of whom Solomon says: ‘A double-minded man is unstable in all his ways’; (James, 1:8) of whom the Lord says: ‘You cannot serve God and mammon.’ (Matthew, 6:24)
This beast has a stone in its eyes, called hyenia; anyone who keeps it under his tongue is believed to foretell the future. It is true that if the hyena walks three times around any animal, the animal cannot move. For this reason men declare that the hyena has magical properties. In a part of Ethiopia the hyena mates with the lioness; their union produces a monster, named crocote. Like the hyena, it too produces men’s voices. It never tries to change the direction of its glance but strives to see without changing it. It has no gums in its mouth. Its single, continuous tooth is closed naturally like a casket so that it is never blunted.
Of the bonnacon In Asia an animal is found which men call bonnacon. It has the head of a bull, and thereafter its whole body is of the size of a bull’s with the maned neck of a horse. Its horns are convoluted, curling back on themselves in such a way that if anyone comes up against it, he is not harmed. But the protection which its forehead denies this monster is furnished by its bowels. For when it turns to flee, it discharges fumes from the excrement of its belly over a distance of three acres, the heat of which sets fire to anything it touches. In this way, it drives off its pursuers with its harmful excrement.