The gwyllgi is a mythical dog from Wales that appears as a frightful apparition of a mastiff with baleful breath and blazing red eyes.
Part of a monster jam done with BlickFen earlier today. He suggested we use the fursona generator. Mine came up as a hellhound with smoke constantly pouring from its mouth (and a collector of knives, but I got lazy).
Mastiff skulls, mmm.
(Check out Blick's result here.)