Yaksha (Sanskrit यक्ष, , yakkha in Pāli ) is the name of a broad class of nature-spirits, usually benevolent, who are caretakers of the natural treasures hidden in the earth and tree roots. They appear in Hindu, Jain and Buddhist mythology. The feminine form of the word is or (Pāli: yakkhī or yakkhinī).
In Hindu, Jain, and Buddhist mythology, the has a dual personality. On the one hand, a may be an inoffensive nature-fairy, associated with woods and mountains; but there is a much darker version of the , which is a kind of cannibalistic ogre, ghost or demon that haunts the wilderness and waylays and devours travelers, similar to the .
In Kālidāsa's poem Meghadūta, for instance, the narrator is a romantic figure, pining with love for his missing beloved. By contrast, in the didactic Hindu dialogue of the ("questions of the "), a dangerous cannibalistic , the tutelary spirit of a lake, threatens the life of the epic hero .
The may have originally been the tutelary gods of forests and villages, and were later viewed as the steward deities of the earth and the wealth buried beneath.
In Indian art, male are portrayed either as fearsome warriors or as portly, stout and dwarf-like. Female , known as , are portrayed as beautiful young women with happy round faces and full breasts and hips.
In the state of Kerala, in South India, Yakshis are depicted as vampire enchantresses.
In Buddhist mythology, the are the attendants of , the Guardian of the Northern Quarter, a beneficent god who protects the righteous. The term also refers to the twelve heavenly generals who guard the Buddha of Medicine (Sanskrit: ; Tibetan: sangs-rgyas sman-bla; Chinese and Japanese: 藥師如來, 薬師如来)
The Alavaka Sutta (SN 10.12) of the Pali Canon details a story where the Buddha was harassed by a Rakshasa, who asked him to leave and then come back over and over. The Buddha refused to leave, whereby the Rakshasa threatened to harm him if he could not answer his questions. The rest of the sutra concerns the question and answer dialogue, and at the end, the demon is then convinced and becomes a follower of the Buddha.