This term, bhuta (Skt. bhūta; Tib. འབྱུང་པོ།, Wyl. ’byung po) in its broadest sense can refer to any being, whether human, animal, or non-human. However, it is often used to refer to a specific class of non-human beings, especially when bhutas are mentioned alongside rakshasas, pishachas, or pretas. In common with these other kinds of non-humans, bhutas are usually depicted with unattractive and misshapen bodies. Like several other classes of non-human beings, bhutas take spontaneous birth. As their leader is traditionally regarded to be Rudra-Shiva (also known by the name Bhuta), with whom they haunt dangerous and wild places, bhutas are especially prominent in Shaivism, where large sections of certain tantras concentrate on them. 
- 84000 Translating the Words of the Buddha.