Pontus (ToPs)

Pontus, sometimes also slept as Pontos, was the Protogenos of the Sea and all the bodies of Water within the Universe. Pontus is also revealed in the Percy Jackson series to be the Protective God of all Pegasi, Horses and most Birds, he is also the Protector and one-time Father of most Sea Creatures and Sea Monsters including the Telekhines.

Out of all the Protogenos, Pontus is said to be the most savage and as unpredictable as the sea, opposing the cold and cruel harshness of Tartarus.

Trivia

 * Pontus or Pontos is the literal Greek word meaning "sea".