Rudi

 is a male wolf cub. His father is Streak and he has an unnamed mother too. He, along with Streak, his mother and another she-wolf traveled with Darren, Mr. Crepsley and Gavner Purl to Vampire Mountain. He got stuck up a tree and was attacked by a rabid bear until Darren, the wolves and the Little People saved him.

Later, after Darren had gone down the river of Vampire Mountain, he met Rudi and the other wolves again to find that he had grown.