Unlike other Faiths, Hinduism does not bring all those who realized Godhead or self-realization under one name, Mystic.
There are Siddhas, Rishis of Different kinds,Munis,Guru,Yogins, Savikalpa and Nirvakalpa,Saints, Sages.
Though there is this common factor of having realized God/Self, there is a minute difference among them.
Please read m posts on Rishis, different kinds.
Siddhas are realized souls, do not die and live eternally.
Yogis reach the State of samadhi.
This is of two kinds.
Savikalpa where the realized soul is seemingly active here.
In Nirvakalpa everything is renounced.
We have yet another classification.
Avadhuta.

Avadhoota (अवधूत avadhūta) is a Sanskrit term from some Indian religions referring to a type of mystic or saint who is beyond egoic-consciousness, duality and common worldly concerns and acts without consideration for standard social etiquette.
Also spelled as Avdhoot, such personalities “roam free like a child upon the face of the Earth”.
An Avadhoota does not identify with their mind or body or ‘names and forms’ (Sanskrit: namarupa).
Such a person is held to be pure ‘consciousness’ (Sanskrit: caitanya) in human form.
Avadhoota play a significant role in the history, origins and rejuvenations of a number of Dharmic Traditions such
as Yoga, Vedanta, Buddhadharma and Bhakti ‘lineage’ (Sanskrit:parampara) even as they are released from standard observances.
Avadhuts are the voice of the avadhuti the channel that resolves the dichotomy of the ‘left hand path’(Sanskrit: Vamamarga; “Vamachara”) and ‘right
hand path (Sanskrit: Dakshinamarga) traditions and left and right channels (otherwise known as the outer channels) of the energetic body, though an
Avadhut may or may not continue such dichotomous rites of the āstika or nāstika Darśana for they are free from sectarian ritual observance and
affiliation.
Feuerstein (1991: p. 105) frames how the term ‘Avadhoota’ came to be associated with the mad or eccentric holiness or ‘crazy wisdom‘ of some antinomian paramahamsa who were often ‘skyclad’ or ‘naked’ (Sanskrit: digambara):
“The appellation “Avadhoota,” more than any other, came to be associated with the apparently crazy modes of behaviour of some paramahamsas, who dramatize the reversal of social norms, a behaviour characteristic of their spontaneous lifestyle. Their frequent nakedness is perhaps the most symbolic expression of this reversal.”
Sacrifice.
Chandra et al.. (1902: p. 20) equates the ‘chodpa‘ (Tibetan: གཅོད་པ, Wylie: chod pa) as a type of Avadhoota:
“ཀུ་སུ་ལུ་པ ku-su-lu-pa is a word of Tantrik mysticism, its proper Tibetan equivalent being གཅོད་པ, the art of exorcism. The mystic Tantrik rites of the Avadhauts, called Avadhūtipa in Tibet, exist in India.”
The rites of chod differ between lineages but essentially there is an offering of their body as food, a blessing to demons and other entities to whom this kind of offering may be of benefit. This leitmotif and sadhana is common to another denizen of the charnel ground, Dattatreya the Avadhoota, to whom has been attributed the esteemed nondual medieval song, the Avadhoota Gita. Dattatreya was a founding adi guru of the Aghor tradition according to Barrett (2008: p. 33):
“…Lord Dattatreya, an antinomian form of Shiva closely associated with the cremation ground, who appeared to Baba Kina Ram atop Girnar Mountain in Gujarat. Considered to be the adi guru (ancient spiritual teacher) and founding deity of Aghor, Lord Dattatreya offered his own flesh to the young ascetic as prasād (a kind of blessing), conferring upon him the power of clairvoyance and establishing a guru-disciple relationship between them.”
Mahānirvāṇatantraṃ
Woodroffe, in his translation of the Mahānirvāṇatantraṃ from the original Sanskrit into English under his nom-de-plume of Arthur Avalon, may be the opening discourse of the archetype of “Avadhoota” to the English reading public, as none of the Avadhoota upanishads were translated amongst the collections of minor upanishads such as the Thirty Minor Upanishads (Aiyar: 1914).The pen-name is play on the magical realm of Avalon and the young later-to-be, King Arthur, within the story-cycle of tales known generally as King Arthur and the Knights of the Round Table; specifically according to Taylor (2001: p. 148), Woodroffe chose the name from the noted incomplete magnum opus, the painting ‘Arthur’s Sleep in Avalon‘ by Burne-Jones.[9] Moreover, Taylor (2001: p. 148) conveys the salience of this magical literary identity and contextualizes by making reference towestern esotericism, Holy grail, quest, occult secrets, initiations and the Theosophists:
“This is quite important to know, for here we have a writer on an Indian esoteric system taking a name imbued with western esotericism. The name at any rate seems to hint at initiations and the possession of occult secrets. The Arthurian legends are bound up with the story of the Holy Grail and its quest. This was a symbol of esoteric wisdom, especially to Theosophists who appropriated the legend. Anyone who named himself after King Arthur or the mystic isle of Avalon would be thought to be identifying himself with occultism, in Theosophists’ eyes.
How to identify an Avadhuta,
The book of Brahmanirvantantra describes how to identify the avadhuts of the following types:
- BramhAvadhoota : An avadhut from birth, who appears in any class of society. Completely indifferent to the world or worldly matters.
- ShaivAvadhoota : Avadhuts who have taken to the renounced order of life (sannyas), often with unkempt long hair (jata), or who dress in the manner of Shaivites and spend almost all of their time in trance (samādhi), or meditation.
- VirAvadhoota : This person looks like a sadhu who has put red colored sandal paste on his body and wears saffron clothes. His hair are very well grown and are normally furling in the wind. They wear in their neck a Rudraksha mala or a string with bones. They hold a wooden stick (danda) in their hand and additionally they always have an axe (parashu) or a damaru (small drum) with them.
- KulAvadhoota : These people are supposed to have taken initiation from the Kaula sampradaya. It is very difficult to recognize these people as they do not wear any signs outside which can identify them from others. The speciality of these people is that they remain and live like usual people do. They can show themselves in the form of Kings or a family man.
The avadhoota represents the pinnacle of spiritual evolution; none is superior to him. Avadhoota means “one who is immortal” (akshara), and who has totally discarded worldly ties. He is verily Brahman himself. He realizes himself to be pure intelligence. He is unmindful of the six infirmities of human birth, namely: sorrow, delusion, old age, death, hunger and thirst. He has shaken off all bondage of the experimental world, and moves
about freely like a child, a madman or one possessed by spirits.
He may be with or without clothes. He does not wear any distinct emblem of any order. He has no desire to sleep, beg or bathe. He views his body as a corpse and subsists on food which comes to him from all classes
. He does not interpret the shastras or the Vedas. For him nothing is righteous or unrighteous, holy or unholy.
He is free of karma. The karmas of this life and past lives are all burnt away, and due to the absence of kartritva (doership) and bhoktritva (desire for enjoyment), no future karmas are created. Only the prarabdha (unalterable) karmas which have already begun to operate will affect his body, helping to sustain it, but his mind will remain unaffected. He will live in this world until the prarabdha karmas are worked out, after which his body will fall off. Then he is said to attain videhamukti (state beyond body consciousness).
Such a liberated soul
never returns to the embodied state. He is not born again; he is immortal. He has achieved the final aim of taking birth in this world.”
Bhad-avadhuta Upanisad, thus: “The Avadhuta is so called because he is immortal ; he is the greatest ; he has discarded worldly ties ; and he is indicated in the meaning of the sentence “Thou art That,”
http://www.ramakrishnananda.com/en/prabhuji/avadhuta/



