A Leviathan in Dungeons & Dragons is a gargantuan water elemental resembling a massive, serpentine creature made entirely of water. Originating from the Plane of Water, it possesses immense strength and can create devastating tidal waves that crush everything in their path. Leviathans can move through water undetected, making them formidable ambush predators. In combat, they use powerful slam and tail attacks, and their bodies are acidic, causing extra damage upon contact. They are resistant to many forms of damage but vulnerable to extreme cold, which can slow them down and make them easier to defeat​