The Goreblaster is mentioned only once in How to Fight a Dragon's Fury, as Big-Boobied Bertha reminisces of home during the Dragon Rebellion. "Sadly, Bertha, Chief of the Bog-Burglars, sharpened her axe, looking back at happier times when she was striding waist-deep in the delightful bogs of home, her faithful Goreblaster swimming by her side." ―How to Fight a Dragon's Fury This passage implies a Goreblaster might be classed as a Bog Dragon, and used as a Hunting Dragon. Because the dragon is swimming while the human is wading through water, it is probably around the size of a dog.