???

??? is a Pre-Hardmode stationary enemy that spawns in the Ocean. When it is killed, it summons The Siren and, in Death Mode, The Leviathan as well. In Revengeance Mode, it can drop the powerful Siren's Heart accessory at any point in the game. It can also be detected by the Lifeform Analyzer.

Trivia

 * When ??? is nearby, the song Siren's Call, which is composed by the artist DM DOKURO, will play.