Arachne
It has also been suggested that Jeremias Gotthelf's nineteenth century novella, "The Black Spider", was heavily influenced by the Arachne story from Ovid's "Metamorphoses". In the novella, a woman is turned into a venomous spider having reneged on a deal with the devil.
Scylla
Scylla made her first appearance in Homer's "Odyssey", where Odysseus and his crew encounter her and Charybdis on their travels. Later myth gave her an origin story as a beautiful nymph who gets turned into a monster.