As I understand it, it was a gift. If you remember, Medusa was once a maiden of Athena. She served Athena but was cast out and punished to a life of solitude after Poseidon raped her inside the walls of the Parthenon, Athena's temple in Athens. read more
Athena also warns Perseus to only look at Medusa through the reflection in his shiny shield. That clever tip definitely saved his life. Perseus shows his appreciation for Athena's help by giving her Medusa's head after he's finished using it. read more
for the reason that whoever looked at them was turned instantly into stone. It seemed that Perseus had been led by his angry pride into making an empty boast. No man unaided could kill Medusa. But Perseus was saved from his folly. Two great Gods were watching over him. read more
Polydectes told Perseus to bring him the head of the gorgon Medusa. Perseus and Medusa Medusa was one of three sisters, the gorgons, but she was the only mortal one. read more