List of characters in the Camp Half-Blood series
Stheno - A Gorgon who is the sister of Medusa and Euryale. In "The Lost Hero," she was mentioned to be among the characters who were brought back to life when the Doors of Death opened. Stheno is described by Percy as appearing as a dumpy old grandmother but with rooster feet and bronze boar tusk sticking out of the corners of her mouth.