A Sloth Brain is a Potion ingredient used in Potions class at Hogwarts School of Witchcraft and Wizardry. The mucus from the brain is a key ingredient in a Dragon dung Fertilizer. Many older students at Hogwarts favour stealing sloth brains from Severus Snape's secret stores, and splattering the mucus on the floors of corridors, much to the displeasure of Argus Filch, the caretaker. In 1991 Fred and George Weasley stole a sloth brain from Professor Snape's stores and hid it somewhere in the Forgotten Grounds. It was found and retrieved by Harry Potter, who brought it to the Potions class.