Even the most well-known mythological creatures sometimes have surprising origins. For example, I was fascinated to learn that Pegasus is the child of the Greek gods Poseidon and Medusa, born from his mother’s neck after the hero Perseus beheaded her.
Below are the origins of five beloved mythological beasts and where their myths originated.

1. Cerberus
Origin: Greek mythology
Appearance: Three-headed dog with a serpent’s tale, lion’s claws, and mane of snakes
Cerberus is a giant, three-headed dog that guards the gates to the underworld. He devours anyone trying to enter or escape, though the legendary musician Orpheus lulls him to sleep by playing a song on a lyre in order to get past. Cerberus’s name is likely derived from the greek words kêr (death) and erebos (darkness).
In modern fantasy, the cerberus myth has inspired a category of creature (the plural is cerberi)—three-headed dogs that are often guardians.

2. Cockatrice
Origin: Greek and Roman mythology
Appearance: A winged creature with the head and feet of a rooster and the tail of a serpent
A cockatrice hatches when a toad sits on a rooster’s egg for nine years. Like the basilisk, the cockatrice’s gaze is lethal and turns anyone unlucky enough to meet their eyes into stone; they’re vulnerable to a rooster’s crow; they’re venomous; and the weasel is the only animal immune to their abilities. The basilisk and the cockatrice are sometimes referred to as the same monster, though other stories differentiate them.

3. Dragon
Origin: Various mythologies
Appearance: A giant serpent with wings
Since dragons are part of so many mythologies from around the world, historians theorize that the stories are based on ancient people discovering dinosaur bones. Myths from Mesopotamia dating back to 2100 BCE describe the Mušhuššu—scaly creatures with the back-legs of an eagle, the front-legs of a lion, and long, thin bodies with a snake-like tongues. They are protectors who bring good fortune.
Other myths include the Egyptian deity Apep, a giant serpent of chaos; the Greek serpent Python, who lives in the center of the earth; the Chinese horned dragons called Qiulong, whose powers are related to water and weather; the Hebrew-based Leviathan, a fire-breathing serpent mentioned in the Bible; and the Aztec deity Quetzalcoatl, a feathered serpent that symbolizes death and resurrection.

4. Griffin
Origin: Greek, Asian, and Middle Eastern mythology
Appearance: A creature with the head and wings of an eagle and the body of a lion
Often guardians of gold and treasure, griffins appear in various mythologies. They’re generally associated with royalty, because the lion is the “king of beasts” and the eagle is the “king of birds.” This is probably why they’re common in medieval Europe heraldry as well. In ancient Egyptian art, griffins are shown trampling people, representing a pharaoh defeating his enemies. In Greek mythology, griffins defend a mountain hiding treasure and are enemies with cyclopses who tried to steal their wealth.

5. Unicorn
Origin: Various mythologies
Appearance: A white horse with a single horn on its forehead
The unicorn appears in early Mesopotamian artwork as well as Indian, Chinese, Hebrew, European, Roman, and Greek mythology. The Greek historian Ctesias describes, during his Indian travels, seeing a white horse with a purple, horned head. The Bible features an untameable horned animal called a Re’em. Aristotle and Julius Caesar claimed to have seen similar creatures. European mythology depicts the unicorn as incredibly intelligent with a soft spot for virgins. Legends suggest the unicorn has healing powers and drinking their blood can prolong life.
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