The ancient Romans conquered the entire Mediterranean. They gave the world legendary badasses, both real and fictional, such as Julius Caesar, Spartacus, and Decimus Meridius Maximus (yes, that’s the correct order). And they were terrified of dolphins.

You can tell a lot about cultural fears from iconography, and to the Romans, dolphins didn’t look like this (an image telling its own creepy tale about the American obsession with cuteness, but that’s a story for a different time):

Instead, they looked like this:

Roman-era floor mosaic on Delos depicting Eros riding on dolphins, c. 120–80 BCE

Thank you, mosaic artist, for making sure the teeth were picked out in black tiles. Your effort is noted and appreciated (not really). Also noted: the demonic yellow eyes and crab-pincer tails, and their size relative to Eros (often depicted riding a dolphin). These are what nightmares are made of.

I first became aware of the creepiness of ancient dolphins when I was in Rome a few years ago. Since then, this question has bothered me: how did the Roman perception of dolphins come to diverge so sharply from our own Flipper-and-Sea World version?

I’m not going to answer that question here. Instead, I’m going to show you some pictures of dolphins and share Benjamin Franklin’s insane theory for why paintings of them are so inaccurate and terrifying. In the end, you will be a little confused but probably not any wiser. I have warned you.

The ancient Greeks loved dolphins. They called them philomousoi, music lovers, because they thought that dolphins danced when they heard music. The poet Bacchylides tells a story about Theseus jumping into the ocean as part of a demigod pissing contest with Minos, only to reappear riding a dolphin. Taras, the mythological founder of the Greek city Tarentum on the south coast of Italy, rode there on a dolphin; the city adopted the image of a man riding a dolphin on their coinage. The Homeric Hymn to Dionysus recounts the story of how Dionysus was taken captive by a ship of pirates and turned them all into dolphins, and Herodotus tells a similar story about how the poet Arion was captured by pirates, jumped overboard, and was rescued by a dolphin and carried to shore.

Remember that story, because it’s going to come back to haunt us later.

Unlike the Roman depictions of dolphins, most ancient Greek pictures of dolphins a) aren’t horrifying and b) appear to have been painted by people with at least a slight awareness of what a dolphin actually looked like. Greek dolphins run the gamut from childishly drawn to friendly-looking to moderately dissatisfied, but they never look like they want to eat your soul.

Here’s a fresco from Knossos that, in spite of being more than 3,500 years old, might be able to pass as a page of Lisa Frank stickers:

Crete, c. 1700–1450 BCE

This dolphin, from about the same period on Santorini, also does not thirst for my blood (although it does look stealthy):

Classical Greek dolphins, while hardly anatomically accurate, probably won’t frighten you and are actually kind of cute: