Roman Mythology

Jaculus

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Tradition: Greek Mythology, Roman Mythology, Italian Mythology
Alternative Names: Jaculus, Iaculus, Javelin Snake
Category: Dragon

The Myth

The Jaculus is a small mythical serpent or dragon, sometimes depicted with wings and occasionally with front legs. It was a creature that attacked from above, hiding among the branches of trees before launching itself at unsuspecting victims like a living javelin.

Its name comes from the Latin word for “thrown,” reflecting the extraordinary force with which the serpent hurled itself through the air. Rather than relying upon venom, the Jaculus killed through the sheer impact of its body. When it struck a victim, the force of the collision caused a fatal wound.

The creature was feared precisely because its attack could come without warning. Hidden high in the branches, it would suddenly spring from its perch and fly through the air toward its target. Pliny described the serpent as being dangerous not merely to a person’s feet, but as something that could actually fly through the air as though launched from a weapon.

Lucan likewise described the Jaculus as a deadly attacker, emphasizing that it was the wound inflicted when the creature struck that caused death, rather than poison.

The same strange idea of a serpent used as a living projectile appears in Malagasy folklore in the tale of the fandrefiala. This small snake was said to carefully calculate its trajectory before hurling itself at a victim with such force that the impact could break a metal pot, killing both the snake and its target.

The Jaculus also appears in the Old Norse Yngvars saga viðfǫrla, where the creature is described not as a tiny serpent but as an enormous dragon. Medieval European tradition likewise preserved the creature as the “javelin-snake,” a serpent that launches itself from trees, as recorded in the Aberdeen Bestiary.

Sources

“Jaculus.” Wikipedia: The Free Encyclopedia. Wikimedia Foundation. Accessed September 26, 2026. https://en.wikipedia.org/wiki/Jaculus

Calopus

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Tradition: Greek Mythology, Italian Mythology, Roman Mythology
Alternative Names: Aeternae, Analopos, Antalope, Antholops, Aptaleon, Aptolos, Pantolops, Jachamur, Jachmur, Jamur, Yamur, Chatloup
Category: Deer

The Myth

The Calopus is a strange antelope-like creature resembling a roe deer in both appearance and size. Its most remarkable feature is a pair of enormous saw-toothed horns growing from its head. These serrated horns are powerful enough to shred branches and even human limbs, but they also have a dangerous weakness: they can easily become entangled in dense thickets.

When a Calopus becomes trapped by its horns in the branches, it cries out. The sound alerts nearby hunters, who can then find the helpless creature and kill it.

The creature was believed to inhabit India, Syria, and the region around the Euphrates, where it was particularly fond of drinking the cool waters of the Euphrates. The Greeks knew the animal as Analopos and by several related names, while the Romans called it Calopus, meaning “pretty foot.” According to Bochart, these names ultimately derived from the Coptic Pantolops.

Alexander the Great was said to have encountered a number of these antelopes during his campaigns in India. One obscure account calls them “aeternae.” The creatures attacked the Macedonian soldiers and pierced their shields with their enormous horns.

Despite their formidable weapons, the Calopuses were overwhelmed by Alexander’s army. Accounts give wildly different numbers for the slaughter, ranging from 5,400 to 8,550 creatures. According to Topsell, this great slaughter was the reason that hardly any of these animals could be seen afterwards.

Several real animals have been proposed as possible inspirations for the Calopus. It may have been based on one of various antelopes, although the moose has also been suggested. The moose’s habit of stripping or shredding trees may have inspired the creature’s distinctive saw-like horns.

The name “Chatloup,” meaning “cat-wolf,” was later popularized by Barber and Rose, but this appears to be a corruption of the original name Calopus rather than an authentic alternative name for the creature.

Sources

Countess Sica. “Calopus.” A Book of Creatures. September 4, 2016. https://abookofcreatures.com/2016/09/04/calopus/

Tranez

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Tradition: Roman Mythology, Italian Mythology, Indian Mythology, Chinese Mythology
Alternative names: Tranez
Category: Cow

The Myth

The Tranez is a small but extraordinarily brave creature, about the size of a hare. Despite its diminutive stature, it possesses remarkable strength and fearlessness.

The Tranez has striking red fur and a natural helmet-like covering on its head. This hard covering protects it from bites, blows, and other dangers in the wild.

The creature was said to inhabit the Orient, referring to the distant lands of the East, including regions extending from India toward China. These lands were traditionally imagined as remote and wondrous places filled with unfamiliar animals, plants, and other marvels.

The Tranez’s small body but exceptional courage was regarded as an example of the Creator’s careful design, demonstrating that every creature was given qualities suited to its particular way of life.

Sources

Van Maerlant, J. (2024). Der Naturen Bloeme (I. Biesheuvel, Trans.), p.74.

Forest Bull

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Tradition / Region: Roman Mythology, Italian Mythology
Alternative names: Ethiopian Bull, Ethiopian Forest Bull, Taurus Aethiopicus, Taurus Aethiopicus Sylvestris
Category: Cow

The Myth

The Forest Bull is a gigantic, tawny-colored breed of wild cattle said to live in the forests of Ethiopia. It is twice the size of an ordinary bull, with red hair, an enormous mouth that opens almost to its ears, and horns capable of turning in any direction. Once raised for combat, its horns remain fixed in that position.

According to ancient accounts, the Forest Bull is one of the fiercest and most savage animals in the world. It is a flesh-eater that hunts herds of wild animals and horses. It is also extraordinarily fast and possesses such great strength that no ordinary weapon can injure it. Spears and arrows are unable to penetrate its hide, while iron weapons are said to rebound from its body.

The Forest Bull uses its movable horns as weapons when fighting. It raises them before attacking and can face an opponent from almost any direction.

Herdsmen living in regions inhabited by the Forest Bulls devised a way to protect their livestock. They dug deep ditches in the ground and allowed the animals to fall into them. Once trapped, the furious bulls were unable to escape and eventually choked on their own rage.

The Troglodytae, a neighboring people who lived in caves, regarded the Forest Bull as the king of beasts. They considered it worthy of the title because it possessed the courage of a lion, the speed of a horse, the strength of a bull, and a hide stronger than iron.

Sources

“Forest Bull.” Wikipedia: The Free Encyclopedia. Wikimedia Foundation. Accessed August 15, 2026. https://en.wikipedia.org/wiki/Forest_Bull

Rhox

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Tradition / Region: Greek Mythology, Roman Mythology, Italian Mythology
Alternative names: Rhogalida / Grape-Spider
Category: Spider

The Myth

The Rhox was a terrifying venomous creature described in ancient Greek and Roman writings. It was usually identified as a spider or phalangion, though its exact nature remains uncertain. Ancient authors associated it with Libya, while similar creatures were also known around the Mediterranean, especially on the island of Crete.

The creature was dark smoky-black or pitch black in color. It possessed a strange mouth lined with teeth in the middle of its body and had short, stubby legs that moved one after another. Although ancient writers called it a spider, these unusual features have led some to believe it may have resembled a centipede or another venomous arthropod instead.

The Rhox was feared for its extraordinarily deadly venom. Ancient physicians claimed that its bite could kill almost immediately, and one of its most unusual symptoms was the appearance of thread-like strands resembling spider webs in the victim’s urine.

Because of its appearance and the lethal effects of its poison, some modern scholars believe the Rhox may have been inspired by the Mediterranean black widow, whose venom was well known throughout antiquity.

Whether it was a true spider or another poisonous creature, the Rhox remained one of the most feared venomous beasts recorded by the natural historians of the ancient Mediterranean.

Sources

A Book of Creatures. (2020, July 6). Rhox. Retrieved June 28, 2026, from https://abookofcreatures.com/2020/07/06/rhox/

Bonacon

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Tradition / Region: Roman mythology, Italian Mythology
Alternate Names: Bonnacon
Category: Cow

The Myth

The Bonacon is a strange and powerful beast, shaped like a great bull with a broad chest, thick hide, and heavy limbs. Around its neck hangs a mane like that of a horse, and its head is unmistakably bovine. Yet its horns, though impressive in size, are twisted inward and curl back upon themselves, useless for combat.

When threatened, the Bonacon does not charge or fight. Instead, it flees.

As it runs, the creature unleashes its true defense. From its body pours a vast stream of burning filth, hurled far behind it with astonishing force. The discharge scorches the earth like fire, filling the air with unbearable heat and stench. Anything it touches is seared, and hunters who pursue the beast are driven back in pain and terror, unable to continue the chase.

Thus the Bonacon escapes without ever turning to face its enemies, leaving them burned and humiliated while it vanishes into the distance. Its survival lies not in strength or weapons, but in a defense so foul and overwhelming that no pursuer dares follow for long.

Sources

Pliny the Elder. (n.d.). Naturalis Historia, Book 8, Chapter 16.

Wikipedia contributors. (n.d.). Bonnacon. In Wikipedia, The Free Encyclopedia, from https://en.wikipedia.org/wiki/Bonnacon

Trebius Niger

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Tradition / Region: Roman Mythology, Medieval European Mythology
Category: Fish, Swordfish

The Myth

The Trebius Niger, or Black Trebius, is a strange and powerful fish known for defying the natural order of the sea. Though small—only about a foot long—it possesses abilities far beyond its size.

The Trebius can halt ships upon the water, clinging to their hulls and robbing them of all movement. Even the strongest vessel, once touched by it, becomes helpless, as if the sea itself has turned solid beneath it. Sailors fear its presence, for no oar or sail can overcome its grip.

The fish is said to change color with the seasons, turning black in summer and white in winter, marking the passage of time as clearly as the sky or the tides.

Most wondrous of all is its power over gold. If a Trebius is preserved in salt, even a small piece of it can be lowered into a deep well and will draw lost gold upward, as though the metal itself longs to return to the surface. For this reason, the fish is both coveted and dangerous, tempting the greedy while punishing the careless.

Unlike other fish, the Trebius does not scatter its eggs in water. Instead, it builds a nest, carefully constructing it before laying its eggs within. Some tales say it gathers seaweed for this purpose; others describe nests found in impossible places, even above the water, defying all expectation.

Later legends add that the Trebius is armed, bearing a sharp beak or pointed snout with which it can pierce ships, sinking them outright despite its small size. In some depictions it appears almost monstrous, with clawed feet, a bearded face, and a strange intelligence in its eyes.

Thus the Trebius Niger is remembered as a creature born of the sea but not bound by its rules:
a fish that stops ships, commands gold, builds nests like a bird, and carries ruin far greater than its form suggests.

Gallery

Sources

A Book of Creatures contributors. (n.d.). Trebius. In A Book of Creatures, from https://abookofcreatures.com/2020/05/15/trebius/

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