Jenny Greenteeth

Jenny Greenteeth is a river hag of north-west England, a grasping water demon long used to frighten children away from dangerous ponds and weed-choked pools. She lurks beneath the green scum of stagnant water — the duckweed that gives her her name — and seizes those who stray too near, dragging them under with long sinewy arms and pallid green skin, her sharp teeth bared. Mothers across Lancashire, Cheshire and Shropshire invoked her to keep the young from the water's edge.

She belongs to a wider family of British 'nursery bogies' — water-dwelling threats like Peg Powler of the Tees and the grindylows of Yorkshire — whose real purpose was protective: a vivid supernatural stand-in for the genuine danger of drowning. The very weed she hides beneath is itself a hazard, masking deep water as solid ground. In this Jenny Greenteeth endures as folklore doing practical work, a monster conjured to keep children alive.