Leviathan, also known as Deep Sea Water is a completed Korean post-apocalypse manhwa written by Lee Gyuntak and illustrated by Noh Miyoung. It is published by Toomics, which also handles its English release.

Taking place on a post-apocalyptic aquatic earth a century after a calamity rose the sea levels, Leviathan follows the adventures of siblings Bota and Rita after their father, Teon Ma, sacrificed his life to save them from a sea monster. The two are soon taken in by a woman called Kana, an acquaintance of their deceased father.