Turns out the Chow Chow isn’t actually alone here, three other breeds are also known for fully blue or blue-black tongues, according to the AKC: the Chinese Shar-Pei, the Eurasier, and the Thai Ridgeback. Like Chow Chow puppies, these breeds typically start out with pink tongues at birth, with the darker pigmentation developing gradually as they grow. It’s a genuinely small, specific list of breeds, which is part of why the trait feels so unusual whenever people come across it for the first time.