Chucklehead was Grimbeard the Ghastly's second son, and Hiccup Horrendous Haddock III's great grandfather. He is the fourth known Chief of the Hairy Hooligans. Not much is known about Chucklehead, but he was described as being the spitting image of Thugheart, who in turn was the spitting image of Grimbeard the Ghastly. He was incredibly stupid, and loved his brother Hiccup Horrendous Haddock II dearly, unlike their eldest brother Thugheart. After Hiccup II's death and Thugheart's banishment, Grimbeard's kingdom fell and he returned to Berk which he then made Chucklehead the new chieftain. Chucklehead eventually married Buffintruda and had two children. Chucklehead later died of old age.