Sea monsters have been seen for at least two thousand years. As well as giant squids and krakens, mermaids have featured in many legends and sightings. Hybrid beings of human female and fish, modern mermaids are generally presented as Disneyesque beauties rather than the often savage and dangerous sirens and other hybrids that appear from antiquity into at least the early modern era.

The year 1527 was a particularly bad one for mermaid attacks, it seems. According to Laurence Andrew’s, The Noble Lyfe and Natures of Man of Bestes, Serpentys, Fowles and Fisshes (British Library MS Royal 2 B VII, f. 97r):

The mermayde is a dedely beste that bringeth a man gladly to dethe. Frome the navyll up she is lyke a woman with a dredfull face, longe slymye here a grete body & is lyke the egle in the nether parte, havinge fete and talentis to tear asonder suche as she geteth. Her tayl is scaled like a fisshe and she singeth a maner of swete song and therwith deceyveth many a gode mariner for whan they here it they fall on slepe commonly & than she commeth and draweth them out of the shippe and tereth them asonder… but the wyse maryners stoppe their eares whan they se her for whan she playth on the water all they be in fear & than they cast out an empty tonne to let her play with it tyll they be past her. This is specifyed of them that have sene it. 

These mermaids were ugly and murderous, singing passing sailors to sleep before tearing them asunder. Fortunately, the slimy-haired beings don’t seem to have been very bright and were easily distracted from their murderous intent by sailors throwing a barrel into the sea for the creatures to play with. How the barrels might be cast while holding one’s hands over one’s ears to ward off the singing spell was not specified.