Manannan Mac Lir is a figure in Irish mythology. He is the son of the sea god Lir and the grandson of the goddess Danu. He is associated with the sea, sailing, and magic. He is often depicted as a shapeshifting god who can take on many forms, including that of a great wave or mist. Manannan Mac Lir was believed to be responsible for protecting sailors from storms and guiding them safely to their destination. He was also said to have magical powers that could grant wishes or bring good luck to those who asked for it. In some stories, he even had control over time itself!