In Greek mythology, which two immortal Gorgons survived after Perseus killed Medusa?

In Greek mythology, Stheno and Euryale were the two immortal Gorgons who survived after Perseus killed Medusa. They were Medusa’s sisters and pursued Perseus after the murder.

The three Gorgons were traditionally Medusa, Stheno, and Euryale. Medusa alone was mortal in the standard genealogy, which is why Perseus could kill her while her sisters remained alive.

Their names are often confused with those of the Graeae, another group of sisters connected with the Perseus story. The Graeae were aged women who shared one eye and one tooth; Stheno and Euryale were Gorgons with the same monstrous family background as Medusa.