Haggo was a bloodrider to Khal Drogo, and a member of his khalasar. Haggo served Drogo faithfully for many years, and was even present during his wedding to Daenerys Targaryen. Haggo was the tallest of the bloodriders, and the strongest. When Viserys III drew steel in Vaes Dothrak, Cohollo was one of the bloodriders ordered to disarm him while Drogo poured a "golden crown" (molten gold) onto his head. In the books, When Drogo fell ill, Haggo joined his fellow bloodriders in trying to kill Mirri Maz Duur. He is engaged by Rakharo and Jhogo, and is eventually overwhelmed and killed. In the show, he remains neutral, and joins one of the two khalasars that was formed following Drogo's death.