This is Rune the Gallinip. Rune is the pet of one of my Harry Potter characters, Lionel.

Gallinips can range in sizes between a hedgehog and a weasel. They are capable of shrinking in size m, shooting there spines and curling up into a protective spiked ball. They are thieves and enjoy stealing just because they can. They are also very curious. There fur colors vary but there spines are always darker.