Sources : Sea-ass
Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Marine monsters 6.37): Onos is a sea-ass, as the Liber Kyrannidarum says, and is eight feet in length; some call it pultum. Burn its flesh in a new pot, and, mixing the ash with its blood kept for this purpose, anoint frenzied people in a bath, and they will be cured; the same is true of [kidney] stones, so much so that they dissolve the stone without injury. - [Badke translation/paraphrase]