B'tub Ring

The B'tub Ring is an accessory in Super Mario RPG: Legend of the Seven Stars. It halves damage taken from elemental attacks, an effect shared with the Amulet. It also has a hidden function in that it is needed to hatch the Mystery Egg into the Lamb's Lure; specifically, Princess Toadstool needs to use the Mystery Egg ten times with the ring equipped. B'tub Rings can be bought from the shop in Marrymore's hotel for 145 coins.