These imaginary beasts fueled nightmares around the world

You may think you don’t believe in monsters—and you certainly aren’t afraid of them—but monsters are fundamental to how humans make sense of the world. For eons, when people have encountered a scientific or natural phenomenon that they don’t understand, they’ve invented a monster to explain it.

Take fossils. Some two thousand years ago, Scythian gold miners in the Gobi Desert stumbled upon skeletons with beaks, claws, and broad shoulder blades jutting out of the sand. They couldn’t imagine the creature that belonged to those bones so they invented one: the griffin—half eagle, half lion, and fierce defender of hidden gold. (What they’d found was probably a protoceratops.)

Elsewhere, monsters took the blame for causing earthquakes. Tribes in the Pacific Northwest told of great battles that split and shook the earth and pointed the finger at A‘yahos, a shapeshifter who took the form of a giant snake. Landmarks mentioned in the tales closely track the Seattle fault line, allowing scientists to date geological events and discover ancient quakes. (This is how earthquakes really work.)

In Japan, the temblor terror is a giant underground catfish called Namazu, who shakes the ground whenever it stirs. Indeed, it’s still a common belief that ordinary catfish can predict earthquakes, folk wisdom that turns out to be supported by research. Today, Japan’s earthquake early warning system uses a catfish as its logo. (Here's how science explains the chupacabra myth.)

Although most of the creatures from the ancient world no longer terrify us, we’re still inventing monsters to embody modern anxieties. Earlier this year, a chicken-woman hybrid called Momo spooked the internet, sparking fears that it would induce kids to commit suicide as part of an online dare—just as kids had answered the Tide Pod challenge by eating poisonous clothing detergent. The trolls that once lurked under bridges now prowl social media platforms.

As long as humans keep nudging the edge of the known world, we will be haunted by the monsters we create.