Fenrir

Fenrir is a beast from the Necronomicon, resembling a giant wolf.

Biography
Fenrir was big wolf, feared by the Norse Pantheon of Deities, who decided to tie him to a bolder, since they believed he would one day grow big enough to devour the world, leading to Ragnarök. This, however, did not appear to be the truth, and he was released in the 21st Century by Lord Bung, with whom Fenrir developed a friendship with.