Rabite's Foot is an accessory that increases Luck by 100, and when a creature consumes 1, they increase their Luck by 5. It can be dropped from Jumbo Cactuar (Normal and Oversoul) or won as a prize in the Chocobo Cup.
An amulet (also known as a "charm") can be any object but its most important characteristic is its alleged power to protect its owner from danger or harm. Amulets are different from talismans as a talisman is believed to bring luck or some other benefit, though it can offer protection as well.
A rabbit's foot in Africa and North America is often carried as an amulet that brings good luck. "Rabite's Foot" is also a reference to the Mana enemy, which debuted in Final Fantasy Adventure. Amusingly, the Rabite does not have a foot.