Percy Jackson and the Olympians: Legends

Oceanus was described by Percy as a huge merman, much larger than the rest, with the upper body of a tall and muscular man, with a long green beard and hair, along with the horns of a bull. Oceanus appeared to be riding a chariot pulled by huge crawfish with a serpent as a weapon. Oceanus can transform his lower body into legs while on land.

Oceanus was shown to not be as arrogant or cruel as his brothers, being the only Elder Titan to not help in the murder of Ouranos. Unlike most immortals, Oceanus actually had a happy marriage with his wife and was faithful to her.

Oceanus is the Titan god of the Oceans , preceding Poseidon as ruler of the world's oceans. While Oceanus was neutral in the first war, his brother Kronos finally convinced him to fight against the Olympians, more specifically his nephew Poseidon. Oceanus enlists Phorcys, Aigaios as well as many ancient monsters against Poseidon, and they battle constantly, leaving Poseidon somewhat weakened. Oceanus and his forces attack Poseidon underwater, making his palace endangered and also making him unable to aid the Olympians in their fight against the monster Typhon. When Percy enters the battle, Oceanus advances and challenges Poseidon himself to a duel. As Percy is leaving, Poseidon engages Oceanus in an enormous clash which causes extremely violent tsunamis and wave, and lights can be seen flashing as the two warriors do battle. When Poseidon chose to aid the Olympians, Oceanus probably did serious damage to Poseidon's palace. After Kronos was defeated, he retreated back into the depths.