Nereid from Poseidon's court

Constellation - Whenever Nereid from Poseidon's
court or another enchantment enters the battlefield under your control, target
creature can't be blocked this turn.
When Percy Jackson was young, Nereids would watch
him with interest at the beach in Montauk and whenever
he was near the ocean because he was the first demigod
son of Poseidon in a long time.