The Chow-Chow is a sturdily built dog, square in profile, with a broad skull and small, triangular, erect ears with rounded tips. The breed is unique by their purple/blue-black tongue which no other breed has except shar-pei's and has very straight hind legs, resulting in a rather stilted gait. The bluish color extends to the Chow-Chow's lips; this is the only dog breed with this distinctive bluish color in its lips and oral cavity (other dogs have black or a piebald pattern skin in their mouths). Another distinctive feature is the curly tail.