In Greek mythology, Thalassa (/θəˈlæsə/; Greek: Θάλασσα, "sea") was the primeval goddess of the sea. Coupling with her male counterpart Pontus, she spawned the tribes of fish. Like the other Primordials, Thalassa was scarcely personified, instead her form was elemental, the body of the sea itself. In the fables of Aesop, Thalassa appears as a woman formed of sea water rising up from her native element.
Poseidon and Amphitrite were the anthropomorphic gods equivalent to Pontos and Thalassa. In late classical times, the two were also confounded with Oceanus and Tethys.
Thalassa was depicted in Roman-era mosaics as a woman half submerged in the sea, with crab-claw horns, clothed in bands of seaweed, and holding a ship's oar.
God of War: Ascension
Like many of her kin, Thalassa fought in the war against the Primordials along with her parents and relatives.
Thalassa appears in the opening scene where is she shown engaging in a fight against Ouranos. Later, she is shown falling to the earth where her deceased body cause the oceans to appear.