Quick rough doodle depicting a scene from Enûma Elish, the Babylonian epic of creation. In Babylonian religion, it was believed that before the creation of the world the entire universe was just one bottomless and endless ocean. The only being that existed was the primordial goddess Tiamat who is often depicted as a massive sea serpent. She would later birth the first generation of gods with the help of her husband, Abzu. These gods would later rebel and kill her, using her corpse to created the firmament (a giant crystal dome that represented sky and space) and the land (Earth). Until then, Tiamat wonders the ocean using her giant fins as sails to propel her towards the endless horizon.
I've been researching Babylonian religion for quite sometime now. I plan on using my knowledge in a future video discussing the origins of the Hebrew Leviathan and Behemoth (which many Young Earth Creationists claim are dinosaurs).