Phaea was an elderly woman who had her pig, the Crommyonian Sow, to destroy villages and farmland that she would raid for food and supplies as well as kill any survivors she found. She was killed by Theseus.
Percy Jackson's Greek Heroes
When Theseus was traveling through a village on his way to Athens, he came across a village that was being terrorized by the old woman and her pig so he agreed to kill them. He found the pig in the remains of a barn and killed it. When she saw what he did, Phaea charged at Theseus to kill him, but ended up getting killed herself.