Moon Shell

The Moon Shell is a Hardmode accessory that can be crafted at the Tinkerer's Workshop. It has the combined effects of the Moon Charm and the Neptune's Shell. Equipping it will turn the player into a Merfolk when entering water (at any time), or into a Werewolf at night. The Merfolk form replaces the Werewolf form if entering water at night.

The buffs from the Moon Charm:

The buff from the Neptune's Shell:

Trivia

 * The Moon Shell resembles a purple Neptune's Shell carved into a crescent moon.