"Of the two energies manifest [spirit and dull matter], beings possessing living force [vegetables, grass, trees and plants] are superior to dull matter [stone, earth, etc.]. Superior to nonmoving plants and vegetables are worms and snakes, which can move. Superior to worms and snakes are animals that have developed intelligence. Superior to animals are human beings, and superior to human beings are ghosts because they have no material bodies. Superior to ghosts are the Gandharvas, and superior to them are the Siddhas. Superior to the Siddhas are the Kinnaras, and superior to them are the asuras. Superior to the asuras are the demigods, and of the demigods, Indra, the King of heaven, is supreme. Superior to Indra are the direct sons of Lord Brahma, sons like King Daksa, and supreme among Brahma's sons is Lord Siva. Since Lord Siva is the son of Lord Brahma, Brahma is considered superior, but Brahma is also subordinate to Me, the Supreme Personality of Godhead. Because I am inclined to the brahmanas, the brahmanas are best of all."
"The creation of the demigods is of eight varieties: (1) the demigods, (2) the forefathers, (3) the asuras, or demons, (4) the Gandharvas and Apsaras, or angels, (5) the Yaksas and Raksasas, (6) the Siddhas, Caranas and Vidyadharas, (7) the Bhutas, Pretas and Pisacas, and (8) the superhuman beings, celestial singers, etc. All are created by Brahma, the creator of the universe.
Purport: As explained in the Second Canto of Srimad-Bhagavatam, the Siddhas are inhabitants of Siddhaloka, where the residents travel in space without vehicles. At their mere will they can pass from one planet to another without difficulty. Therefore, in the upper planets the inhabitants are far superior to the inhabitants of this planet in all matters of art, culture and science, since they possess brains superior to those of human beings. The spirits and jinn mentioned in this connection are also counted among the demigods because they are able to perform uncommon functions not possible for men."
"I myself [Brahma], Lord Siva, Lord Visnu, great generators of living beings like Daksa and Prajapati, yourselves [Narada and the Kumaras], heavenly demigods like Indra and Candra, the leaders of the Bhurloka planets, the leaders of the earthly planets, the leaders of the lower planets, the leaders of the Gandharva planets, the leaders of the Vidyadhara planets, the leaders of the Caranaloka planets, the leaders of the Yaksas, Raksas and Uragas, the great sages, the great demons, the great atheists and the great spacemen, as well as the dead bodies, evil spirits, satans, jinn, kusmandas, great aquatics, great beasts and great birds, etc.--in other words, anything and everything which is exceptionally possessed of power, opulence, mental and perceptual dexterity, strength, forgiveness, beauty, modesty, opulence, and breeding, whether in form or formless--may appear to be the specific truth and the form of the Lord, but actually they are not so. They are only a fragment of the transcendental potency of the Lord.
Purport: "Those in the list given above, beginning from the name Brahmaji, the first living creature within the universe, down to Lord Siva, Lord Visnu, Narada and other powerful demigods, men, supermen, sages, rsis, and other lower creatures of extraordinary strength and opulence, including the dead bodies, satans, evil spirits, jinn, aquatics, birds and beasts, may appear to be the Supreme Lord, but factually none of them is the Supreme Lord; every one of them possesses only a fragment of the great potencies of the Supreme Lord. The less intelligent man is surprised to see the wonderful actions of material phenomena, as the aborigines are fearful of a great thunderbolt, a great and gigantic banyan tree, or a great lofty mountain in the jungle. For such undeveloped human beings, merely the slight display of the Lord's potency is captivating. A still more advanced person is captivated by the powers of the demigods and goddesses. Therefore, those who are simply astonished by the powers of anything in the creation of the Lord, without any factual information of the Lord Himself, are known as saktas, or worshipers of the great powers. The modern scientist is also captivated by the wonderful actions and reactions of natural phenomena and therefore is also a sakta. These lower-grade persons gradually rise to become sauriyas (worshipers of the sun-god) or ganapatyas (worshipers of the mass of people as janata janardana or daridra-narayana, etc., in the form of Ganapati) and then rise to the platform of worshiping Lord Siva in search for the ever-existing soul, and then to the stage of worshiping Lord Visnu, the Supersoul, etc., without any information of Govinda, Lord Krsna, who is the original Lord Visnu. In other ways some are worshipers of race, nationality, birds, beasts, evil spirits, satans, etc. The general worship of Sanideva, the lord of distressful condition, and Sitaladevi, the goddess of smallpox, is also common to the mass of people, and there are many foolish men who worship the mass of people or the poor class of men. So different persons, societies and communities, etc., worship some of the potent manifestations of the Lord, wrongly accepting the powerful object as God. But in this verse it is advised by Brahmaji that none of them is the Supreme Lord; they are only borrowed plumes from the original Almighty Lord Sri Krsna. When the Lord advises in Bhagavad-gita to worship Him alone, it is to be understood that worshiping Lord Krsna includes worshiping all that is mentioned, because He, Lord Krsna, includes everyone."
"Thus mother Yasoda began to chant different names of Visnu to protect the child Krsna's different bodily parts. Mother Yasoda was firmly convinced that she should protect her child from different kinds of evil spirits and ghosts--namely Dakinis, Yatudhanis, Kusmandas, Yaksas, Raksasas, Vinayakas, Kotaras, Revatis, Jyesthas, Putanas, Matrkas, Unmadas and similar other evil spirits, who cause persons to forget their own existence and give trouble to the life airs and the senses. Sometimes they appear in dreams and cause much perturbation; sometimes they appear as old women and suck the blood of small children. But all such ghosts and evil spirits cannot remain where there is chanting of the holy name of God."
Krsna Book, Chapter 6
"The evil witches known as Dakinis, Yatudhanis and Kusmandas are the greatest enemies of children, and the evil spirits like Bhutas, Pretas, Pisacas, Yaksas, Raksasas and Vinayakas, as well as witches like Kotara, Revati, Jyestha, Putana and Matrka, are always ready to give trouble to the body, the life air and the senses, causing loss of memory, madness and bad dreams. Like the most experienced evil stars, they all create great disturbances, especially for children, but one can vanquish them simply by uttering Lord Visnu's name, for when Lord Visnu's name resounds, all of them become afraid and go away."
"O club in the hand of the Supreme Personality of Godhead, you produce sparks of fire as powerful as thunderbolts, and you are extremely dear to the Lord. I am also His servant. Therefore kindly help me pound to pieces the evil living beings known as Kusmandas, Vainayakas, Yaksas, Raksasas, Bhutas and Grahas. Please pulverize them."
"O best of conchshells, O Pancajanya in the hands of the Lord, you are always filled with the breath of Lord Krsna. Therefore you create a fearful sound vibration that causes trembling in the hearts of enemies like the Raksasas, pramatha ghosts, Pretas, Matas, Pisacas and brahmana ghosts with fearful eyes."
"The conditioned souls are embarked on a sojourn of successive births from 84 lakhs of varieties of generating organs. They are differentiated into different orders of beings as devas, danavas, raksasas, manavas, nagas, kinnaras, and gandharvas. These jivas, from Brahma down to the small insect, are infinite in type."
"The demons or demoniac persons--the Gandharvas, the Siddhas, the Vidyadharas, the Caranas, the Yaksas, the Raksasas, the Pisacas, the ghosts and the hobgoblins--are incapable, by nature, of worshiping You or becoming Your devotees. Instead of becoming Your devotees, they simply become impediments on the path of devotion."
Krsna Book, Chapter 85
Bhaktivedanta Book Trust. Excerpted from various texts and purports of HDG A.C. Bhaktivedanta Swami Srila Prabhupada.