Halloween
A/N: the plot takes place three years before Harry's first arrival at Hogwart's
Although the Headmaster had many personal merits, some of his ideas simply qualified him as a patient of the closed ward of St. Mungo's. So she couldn't understand why the staff agreed to this particular idea almost inanimously. Of course with the exception of Snape, who only snorted, while hearing, what they were supposed to do to satisfy a clearly handicaped sense of humor of the Headmaster.
Unfortunately, she agreed, assuming that this Halloween project might at most slightly undermine her authority. In a skin-tight costume she was feeling weird... And she kept stumbling over a tail.
'You look beautiful, Minerva' said Dumbledore, as soon as he spotted her in the crowd. 'Our Hogwart's catwoman.'