The 21-year-old 'Love Me Harder' singer posted a photo of the pooch on her Instagram account and revealed she has named it after the fictional godfather in the 'Harry Potter' series, because of his dark coat of fur.
Captioning the image, she wrote: "Sirius black newest member of the puppy posse ......... The puppy breath is out of this world I am going to be the Edie Beale of dogs (sic)."
The puppy is the latest four-legged friend to be welcomed into the star's home, as she already has six-month-old rescue dog Cinnamon - which she welcomed in December - as well as Fawkes, Coco, Toulouse and Ophelia.