Moon Shell

The Moon Shell is a hardmode accessory which 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 Werewolf every night, and a Merfolk when entering water, regardless of the time of day. If it is night and you enter the water, the Werewolf buff will be removed and replaced with the Merfolk buff until you exit the water.

Trivia

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