ok it's a "dobermann", a normal dog

'cause a normal wolpertinger would be a dog-like humanoid creature
same apperance as from a dog except that a wolpertinger is 2m-3m big and walks
on 2 legs(also able to walk on all 4) and has little horns on the head
and that a wolpertinger is an amazing fighter and very aggressive.

well actually if you want to read a story about a wolpertinger then
read "Rumo" a book written in german(sorry^^)
I absolutely suggest this book!