This isn't her true form. Shes actually magical like Jake except that shes a wolf.
She admires Finn amazingly because she has never seen a human before so she takes on a human form most of the time. The only thing she can't get rid of is her ears and tail.
Other then stretching like Jake, she doesn't have any other powers.
She also changes clothes from jeans to shorts, converses to boots, and wears a winter hat a lot. (kinda like me)