Synonyms for Hag (same or very similar meaning)
WordNet sense 1 (an ugly evil-looking old woman):
crone, witch, beldam, beldameWordNet sense 2 (eellike cyclostome having a tongue with horny teeth in a round mouth surrounded by eight tentacles; feeds on dead or trapped fishes by boring into their bodies):
hagfish, slime eelsFrom the ODE community, based on WordNetadd/edit