Sources : Sea-viper

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Fish 7.90): Sea-vipers are very small marine fish, little more than one cubit. On the head, above the eyes, they carry a small horn, sharp and deadly. For anyone it wounds with the horn, it infects with poison. The cautious fishermen, having caught this fish, cut off its head. But the rest of the body yields to the uses of men; for it is very versatile. - [Badke translation/paraphrase]