Yaksha

(Sanskrit यक्ष) or Yakkha (Pāli यक्ष) 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).
See more at Wikipedia.org...

(n.)
A kind of demigod attendant on Kuvera, the god of wealth.
  

[Hindu] In Hindu myth, Yakshas are chthonic semi-divine beings, half god and half demon. They live under the earth in the Himalayas where they guard the wealth of the earth (gems, gold, silver, etc.). They are led by Kubera, the god of wealth. Like their leader, they have all fat bellies and plump legs. They have no special characteristics, are not violent, and are therefore called punyajana ("good beings"). Kubera's epithet is Punyajaneshvara.

Yaksha yaksa (Sanskrit) [from the verbal root yaksh to devour] A class of ethereal, astral, or semi-astral beings, regarded as attendants of Kubera or Kuvera, the deity of riches; occasionally they are associated with Vishnu. The yakshas are variously described as the sons of Pulastya, Pulaha, Kasyapa, Khasa, or Krodha. One legend represents them as springing from the feet of Brahma, while one Puranic account shows them as springing from the body of Brahma with the rakshasas and immediately attempting to devour his body. However, frequently the yakshas are regarded as beings beneficent to humans. In Kalidasa's Meghaduta, the hero is a yaksha, represented as a banished lover who employs a cloud to bear a message to his beloved.
In later popular folklore the yakshas are associated with and classed with the pisachas, and therefore regarded with dread and made responsible for many demoniacal obsessions. "In esoteric science they are simply evil (elemental) influences, who in the sight of seers and clairvoyants descend on men, when open to the reception of such influences, like a fiery comet or a shooting star" (TG 375).