Medusa received help. He received a mirrored shield from Athena, gold, winged sandals from Hermes, a sword from Hephaestus and Hades's helm of invisibility. Since Medusa was the only one of the three Gorgons who was mortal, Perseus was able to slay her while looking at the reflection from the mirrored shield he received from Athena. During that time, Medusa was pregnant by Poseidon. When Perseus beheaded her, Pegasus, a winged horse, and Chrysaor, a giant wielding a golden sword, sprang from her body. Jane Ellen Harrison argues that "her potency only begins when her head is severed, and that potency
Andromeda (constellation) daughter to Cetus. She was chained to a rock by the sea but was saved by the hero Perseus, who in one version of the story used the head of Medusa to turn the monster into stone; in another version, by the Roman poet Ovid in his Metamorphoses, Perseus slew the monster with his diamond sword. Perseus and Andromeda then married; the myth recounts that the couple had nine children together – seven sons and two daughters – and founded Mycenae and its Persideae dynasty. After Andromeda's death Athena placed her in the sky as a constellation, to honor her.