Also yakusha 薬叉 (Sk: yaksa), a class of semi-divine beings usually considered to be of a benevolent and inoffensive disposition but sometimes also classed with malignant spirits such as the *rasetsu 羅刹. The female counterparts are called yashanyo 夜叉女 (Sk: yaksi, yaksini) and were regarded in particular as tree nymphs or symbols of fertility.
Yasha were adopted into Buddhism at an early stage, and many finely executed stone reliefs and statues are to be found at Sanchi, Mathura, and elsewhere in India. Eventually they came to be included among the eight classes of being that protect Buddhism *hachibushū 八部衆. They also act as attendants of *Bishamonten 毘沙門天, who is said to have under his command “eight yasha generals” yasha hachidaishō 夜叉八大将. The Twelve Divine Generals *jūni shinshō 十二神将 who protect devotees of *Yakushi 薬師 and the Sixteen Good Gods jūroku zenjin 十六善神 who protect the Daihan'nyakyō 大般若経 (Great Wisdom Sutra) also belong to the category of yasha, while Kongōshu 金剛手 is often described as a yasha general, and the goddess *Kariteimo 訶梨帝母 is said to have been a yashanyo who was converted to Buddhism. In China and Japan, it has been their role as tutelary spirits that has received the greatest emphasis, and therefore they are generally represented clad in armor. They have come to be popularly regarded as demons of fearsome appearance who harm and even devour humans.