Akrisios
Akrisios (or Acrisius) is a person in Greek mythology. He was the King of Argos. He is the father of Danaë, and grandfather of Perseus.
Akrisios was told by an oracle that he would be killed by his grandchild. Because of that he put his daughter Danaë in a tower where noone was allowed to enter, so she could not have a child. But the god Zeus could enter in the form of a golden rain, and with him her child was Perseus.
Akrisios then put Danaë and her baby Perseus in a box and threw it into the sea. But Zeus tells the sea-god Poseidon to help them, and so Danaë and her son come to the island Seriphos. There they are found by Polydectes, who lets them live with him.
A long time after that, the grown up Perseus takes part in some funeral games. During the games Perseus throws a discus, which accidentally hits Akrisios. Akrisios is killed by it: he was killed by his grandchild, like the oracle's prophecy said.