Bk VIII:843-884 The fate of Erysichthon and his daughter Mestra.
"Now hunger, and the deep pit of his gut had consumed his wealth, but even so, Famine worked unabated and his burning appetite was unappeased. Eventually, when all he owned was inside him, only his daughter, Mestra, was left, a girl whom the father was not worthy of. Having nothing, he tried to sell her too. The honourable child refused to accept a possessor, and stretching her hands out over the waves of the shore, she cried: 'You god, who stole away the prize of my virginity,' for Neptune had stolen it, 'save me from slavery.' He did not scorn her prayer. Although the buyer had been following her, and had seen her a moment ago, the god altered her shape, giving her a man's features, and clothes appropriate to a fisherman.
Her purchaser looked at her, and said: 'O, you who control the rod, and hide your bronze hook in a little bait, may you have calm sea, and gullible fish, that feel nothing of the hook until they bite. Tell me where she is, the girl with shabby clothes and straggling hair, who stood here on this beach a moment ago (since I saw her, standing on the beach): there are no footprints further on!' She sensed the god's gift was working well for her, and delighted that he was asking her for news of herself, replied to his question: 'Forgive me, whoever you are: I have had no eyes for anything except this pool: I have been occupied taking pains over my fishing. To convince you, and may the sea god help me in these arts of mine, no man has been on this beach, except myself, for a long time, and no woman either.'
He believed her, and turning round on the sand, having been outplayed, departed. Then her true shape was restored. When her father realised that she could change her shape, he often surrendered Mestra to others, so that she, escaping in the form of a mare, or a bird, or again as a heifer or a hind, repeatedly obtained her price, dishonestly, for her gluttonous father.
In the end when the evil had consumed everything they had, and his grave disease needed ever more food, Erysichthon began to tear at his limbs and gnaw them with his teeth, and the unhappy man fed, little by little, on his own body."
"But why do I entertain you with stories of others?" said Acheloüs, "Indeed, young man, I have often changed shape myself, though the number of shapes I can achieve is limited. Sometimes I am seen as I am now: sometimes I become a snake: or, again, the lead bull of the herd, my power in my horns – horns, when I still had two. Now one side of my brow has lost its weapon, as you can see for yourself." His words were followed by a sigh.