Historically, mapmaking was a fairly imprecise task . . .to fill blank areas on the maps, mapmakers used to include textual/graphic warnings of the dangers of going into uncharted territory. Such warnings took the form of sea serpents, dragons, mythical and, sometimes, even real creatures. The actual line "Here There Be Dragons" has been found only once, on the 16th-century Lenox Globe — but is too cool to give up.
A macro picture of Lepidonotopodium piscesae, a polychaete or bristle worm. These critters survive the intense pressures of our deepest oceans where sunlight never penetrates… (h/t Why Evolution Is True)