Tibetan Mastiff. The Tibetan Mastiff (Tibetan: འབྲོག་ཁྱི། འདོགས་ཁྱི། སེང་ཁྱི།, romanized: Drok chi/kyi; 'Dok kyi; Seng kyi, lit. 'Nomad-dog; chaining dog; lion-dog', THL: Do khyi, Wylie: 'brog khyi; 'dogs khyi; seng khyi)[a] is a large size Tibetan dog breed. Its double coat is medium to long, subject to climate, and found in a wide variety of colors, including solid black, black and tan, various shades of red (from pale gold to deep red) and bluish-gray (dilute black), and sometimes with white