Alicorn Amulet

The Alicorn Amulet is a magical amulet that is featured in the episode Magic Duel. According to a book that the main characters find in Twilight Sparkle's library, the Alicorn Amulet blesses the wearer with "untold powers." However, the more the bearer uses the amulet, the more it corrupts him or her. The book goes on to say that the amulet has an in-built magical lock that prevents any pony other than the bearer from taking it off. However, the amulet has its limits, as it cannot perform spells that are considered simply impossible, such as duplicating a target, making a pony play ten instruments at once, or changing a pony's gender.