Neptune's Shell

The Neptune's Shell is a Hardmode accessory that aids underwater performance by allowing indefinite breathing underwater, enabling swimming via the key, and eliminating the usual slow movement speed caused by water. On the, it has a 2% / (1/50 / ) chance to drop from Creature from the Deep during a Solar Eclipse event. On the s and s, it is only obtained through crafting.

Entering water with this accessory equipped transforms the player into Merfolk, a buff with no time limit. While in this form, water's usual effects are negated. The breath meter will not decrease, therefore effectively preventing drowning, and movement through water is as quick as it would normally be on dry land. Holding the key also makes the character swim (fly continuously upward) in water, while falling is just as fast as falling through the air.

The Neptune's Shell can be considered an upgrade from the Diving Gear in most respects, but lacks the underwater lighting of the Jellyfish Diving Gear and the extra mobility on ice of the Arctic Diving Gear.

Trivia

 * The name of the item refers to the Roman god, Neptune, god of the sea

History
Coquillage de Neptune