When one thinks of creating terrifying hybrid animal concoctions, the humble chicken is probably somewhere lower on the list of preferable spare parts… unless of course you are talking about the cockatrice. This horrifying creature is said to be created when an egg laid by a rooster is incubated by either a snake or a toad, eventually out from which slithers a winged monster with the head and legs of a rooster and the body of a snake, or dragon. Still not scared? Well, these creatures come equipped with a death stare that will instantly kill anyone that looks into their eyes, as well as emitting poison from their breath & in some versions, skin.

Often confused with the basilisk, the two are closely related, the main difference being that the basilisk is the egg of a toad or serpent hatched by a rooster rather than the opposite way around, still rendering the two close cousins in terms of appearance and magical properties. While the basilisk is possibly better known in our times with its pop-culture re-emergence in the Harry Potter series, the cockatrice has a few cameos in a much older popular book… the King James Bible. In Isaiah 59 we learn that to “hatch cockatrice’ eggs” makes a wonderful metaphor for sinning through lies and mischief… sadly for the cockatrice the revised version replaced him with the basilisk, who in turn was ousted for a boring old viper by the time the international standard version was released. However, that didn’t stop Pope Leo IV from banishing one from the Roman underground during the 9th century.

Basic biology teaches us that is impossible for roosters to lay eggs, so where did the idea of rooster eggs come from? Sometimes (often when they are just starting to lay) a chicken may produce an irregular egg, colloquially known as a “fart egg”. These eggs are much smaller than usual, and do not possess a yolk; some believed that they were laid by the rooster. It was also believed that snakes (or toads) could easily steal these smaller eggs and incubate them, thus producing a cockatrice. Folklore has it that upon finding one of these eggs you should immediately toss it over your house, so it clears the roof. Failing that, cockatrices can be killed either by gazing at themselves in the mirror or hearing a real cock crow. It is said that medieval travelers through Europe and the UK often carried a rooster with them for the express purpose of killing any basilisk or cockatrice they might encounter on their journeys.

Don’t care for roosters? Try a weasel; they are one of the few animals said to be impervious to the death stare and poison of the cockatrice and will actively attack any they come across.

The Greek historian Pliny the Elder had some things to say about the cockatrice. He gives an account of watching a Pharaoh’s rat (otherwise known as a mongoose) watching a plover (a type of bird) enter the open mouth of a Nile crocodile to clean its teeth, which might explain the avian/reptilian origins of this mythical beast. He also noted the following: “Anyone who sees the eyes of a basilisk serpent (basilisci serpentis) dies immediately. It is no more than twelve inches long and has white markings on its head that look like a diadem. Unlike other snakes, which flee its hiss, it moves forward with its middle raised high. Its touch and even its breath scorch grass, kill bushes and burst rocks” (Natural History, Book 8, 33). Then again, Pliny also claimed that giant dragons were in a state of war with mammoth elephants in the mysterious land of India, so he makes for a questionable tour guide.

If you’re still feeling adventurous and want to see a cockatrice in the flesh, remember to pack a rooster, a weasel, or a 9th century Pope (yes, the last item might require bending the laws of space-time, but anything can happen in cockatrice country).