Complex sentence: Wøtan, whose name is apparently a joke on the Nordic god Wotan, is the shepherd's dog, walks around the flock at moderate speed, but starts to run when he sees Sven.
Split into simpler sentences: Wøtan, whose name is apparently a pun on the Nordic god Wotan, is the shepherd's dog. He walks around the flock at moderate speed, but starts to run when he sees Sven.