The Fagiggily Gland is an organ unique to Fairies and Anti-Fairies and gives them the ability to shapeshift into different objects or creatures. Fagiggly glands can fail which will cause them to need a transplant. If the fairy has no siblings, they need to get their transplant from their Anti-Fairy. This helps them both because if the Fagiggily Gland of a Fairy goes bad, the same gland of their Anti-Fairy counterpart goes "good", which is looked down upon by Anti-Fairies.