| Neptune's Shell
|| Accessory – Crafting material
| Max stack
|| Transforms the holder into merfolk when entering water
| Grants buff
|| Merfolk (buff)
| Buff duration
|| While underwater
| Buff tooltip
|| 'Can breathe and move easily underwater'
| Internal Item ID: 497
Neptune's Shell is a Hardmode Accessory that aids underwater performance by allowing indefinite breathing underwater, enabling swimming via the ↷ Jump key, and eliminating the usual slow movement speed caused by water.
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 all eliminated. The breath meter is eliminated entirely, and movement through water is as quick as it would normally be on dry land. Holding the ↷ Jump key also makes the character swim (fly continuously upward) in water, while falling is just as fast as falling through the air.
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.
- Wearing the Fish Bowl will not activate the Merfolk buff.
- Swimming speed nears that of flying through air with Wings.
- Swimming in Honey activates all the perks of Merfolk but does not allow you to move at full speed.
- Swimming in Lava does not activate the Merfolk form.
- Landing in and "jumping" from water alone (by swimming up past the surface), without touching land, does not reset flight time for Wings or variants of Rocket Boots.
- The Merfolk form overrides all clothing and equipment graphics. No armor or clothing will show on your character while Merfolk is active.
- The Merfolk buff overrides the Werewolf buff, replacing the graphics and cancelling the bonuses granted by the Moon Charm during the night.
- The Merfolk form is affected by Dyes.
- Neptune is the Roman god of the sea.
- 220.127.116.11: No longer craftable, now drops from critters in the deep
- 1.2: Now used in the crafting of the Moon Shell.
- 1.1: Introduced.