One of the three perilous encounters that Perseus experience during his adventure is when he was asked to kill Medusa, the beast with snakes as hair that will turn everybody who stares at the snakes into stones. The other one is when Perseus stole the eyeball from the Gray women and hostaged it in exchange for the location of the nymphs of the north. It was also a perilous experience when he had to fight and kill the serpent who is going eat and kill Andromeda.