Leviatitan

The Leviatitan is a Hardmode ranged weapon which is dropped by the Leviathan and Anahita. It rapidly fires sea water blasts, with a 1/4 chance of firing a poisonous sea water blast instead, which inflicts both the Poisoned and Venom debuffs onto enemies. Despite a fairly low projectile velocity, the Leviatitan inflicts huge DPS at no ammo cost, making it a valuable asset in long boss fights.

Trivia

 * The name of this weapon is a portmanteau of the words "Leviathan" and "Titan".