It seemed the 22-year-old actress had cast a spell on the little pooch to turn it into an unnatural pink shade, reported Sun online.
The Bichon Frise was her friend's pet and Watson, herself dressed in black from head to toe, was walking the puppy in hip Bethnal Green, East London.
But it turns out there was no wizardry as the curly lap dog had had a 90-pound dye treatment at a grooming parlour.