Shape-shifting creatures are popular all around the world. Scotland has Selkies, Europe has Werewolves, and Africa has Werehyenas. The idea of people turning into animals to enact evil isn't a new one. Humans have always sought ways to explain the darker actions of their brethren, or an excuse to ostracize the unwanted other.
Bouda/Buda - Actually, That's Offensive
This Evil Eye, Buda, grants its wielder the power to transform into a hyena at night. Why would one want such a power? Do they use it to kill their enemies? The answer is that the Werehyena goes to the graveyard and digs up the graves of dead Christians to gnaw on their bones.
That's where the truth comes in. Legends of the Buda, and shape-shifters in general, are used as a method of Othering. Where there are no clear racial distinctions, people will target the next best thing to find an enemy. Sometimes these divisions are drawn along linguistic, religious, sexual, or political lines. They are always used to dehumanize an enemy, which makes it easier to commit violence against them.
The Ethiopian people are mostly Christians with a similar racial background. One small group exists called the Beta Israel, who are better known as the Ethiopian Jews.
Jews have long been persecuted by Christians. The Beta Israel were excluded from certain professions, just like Jews in Medieval Europe, and had to specialize in other trades. Specifically metalwork and pottery.
Superstitious people believed that the turning of clay and ore into useful materials through the use of fire was some kind of magic. Thus, they resented those who worked the gifts of the Earth.
Along with the power to turn rocks into useful tools, the Beta Israel were accused of being able to transform into Hyenas. No animal is as abominable as the Hyena after all. It eats rotten meat, crushes bones, and is more than capable of killing a human. Add to that the laughter, and you have a monster.
How does someone become a Buda? It's a pact made by an ancestor with a demon. In return the human receives knowledge of some trade, like metalworking, and the power to become a Hyena.