The Yakkhas have a distinct language, culture and tradition. The Yakkha language is a Tibeto-Burman language. The onset of modernism and influence from external factors have caused a rapid disappearance of the Yakkha language.^[9] The Yakkhas practice the Kirati religion of nature worship. There are 32 family names (Thar) in the Yakkhas. Each Thar also has a sub-group called the Sameychong. Marriages do not occur between families sharing the same Sameychong.

Source: https://en.wikipedia.org/wiki/Yakkha_people