Aspidochelone

The aspidochelone stands as one of the most fascinating creatures in medieval bestiaries, originating from the tradition of the Physiologus. This legendary sea beast appears in various forms—sometimes described as an enormous whale, other times as a colossal sea turtle, or occasionally as a monstrous marine creature with massive spines along its back. Regardless of its specific form, the aspidochelone's defining characteristic remains its extraordinary size, so immense that sailors regularly mistake it for a small island complete with sand, soil, and vegetation.

The name itself reveals its nature—"aspidochelone" combines the Greek words aspis (meaning "shield" or "asp") and chelone (meaning "turtle"), reflecting its hybrid characteristics. According to the legends, this creature employs a deadly hunting strategy: it rises to the ocean's surface, creating the perfect illusion of a welcoming island. Unsuspecting sailors, deceived by this appearance, anchor their ships and come ashore on what they believe is solid ground. Once they establish camp and light fires, the aspidochelone feels the heat and suddenly submerges, dragging both ships and sailors to their doom in the depths below.

The creature is also said to emit a sweet fragrance that attracts fish, which it then devours. In the moralistic teachings of the Physiologus and subsequent bestiary traditions, the aspidochelone serves as an allegory for Satan, who similarly deceives those he wishes to destroy.

The earliest documented version of this legend appears in the Physiologus (2nd century AD):

"There is a monster in the sea which in Greek is called aspidochelone, in Latin 'asp-turtle'; it is a great whale, that has what appear to be beaches on its hide, like those from the sea-shore. This creature raises its back above the waves of the sea, so that sailors believe that it is just an island, so that when they see it, it appears to them to be a sandy beach such as is common along the sea-shore. Believing it to be an island, they beach their ship alongside it, and disembarking, they plant stakes and tie up the ships. Then, in order to cook a meal after this work, they make fires on the sand as if on land. But when the monster feels the heat of these fires, it immediately submerges into the water, and pulls the ship into the depths of the sea."

The Alexander Romance also references a similar creature in Alexander's letter to Aristotle: "After they landed on the so-called island and an hour passed, suddenly it proved to be no island, but a monster which plunged into the sea. We shouted and it disappeared, but some of my companions met a wretched death, among them my best friend." In various versions of this text, similar sea monsters appear—identified as "a lobster" in the Armenian version or "beasts that are called crabs" by Leo Archpriest.