A Niffler is a treasure-hunting creature with a long narrow snout. They are very attracted to shiny things, which makes them wonderful for locating anything metallic or shimmery, but they might bite if a person is wearing any jewellery. Nifflers are kept by Goblins to burrow for treasure.
Nifflers are gentle creatures, and can be affectionate to its owners but will also destroy belongings and property if kept in a house. Nifflers live twenty feet below the ground in lairs, and can produce six to eight young in a single litter.
During Dolores Umbridge's reign as Headmistress of Hogwarts School of Witchcraft and Wizardry, Lee Jordan used a Hover Charm to levitate Nifflers through her office window to wreck the place. Umbridge blamed Hagrid for it.