Brilliant Three-Headed Dog
Brilliant Trapdoor Chamber
Third-Floor Corridor, Hogwarts Castle
Very few witches or wizards have encountered a Three-Headed Dog in the wild. Even fewer have encountered one in the third-floor corridor of Hogwarts Castle. Those that have can attest that three heads are, in fact, deadlier than one. Because of that ferocity, Fluffy, Hagrid's pet Three-Headed Dog, was even entrusted with guarding the Philosopher's Stone.