Srila Bhaktivinoda Thakura in his Sri Caitanya Siksamrita describes the demons killed during Sri Krishna's Vrindavana pastimes and the anarthas (unwanted things) that they represent.
Bhaktivinoda Thakura says: "The devotee who worships the holy name should first petition the Lord for the strength to cast out all these unfavorable tendencies and should pray thus before Lord Hari ( Balaram - Nityananda ) on a daily basis. By doing this regularly, the devotee's heart will eventually become purified. Sri Krishna has killed a number of demons which may arise in the kingdom of the heart, so in order to destroy these problems, a devotee must cry very humbly before the Lord and the Lord will then nullify all contaminations."Putana - the pseudo guru Sakatasura (the cart demon) - carrying the burden of a cart-load of old and new bad habits, lethargy and vanity. Trinavarta (the whirlwind demon) - false pride which comes from material scholarship, which leads to bogus philosophies. Deliverance of Nalakuvara and Manigriva (breaking the twin arjuna trees) - Arrogant pride which comes from puffed-up prestige, which is rooted in a madness for wealth. Vatsasura (the calf demon) - a childish type of mentality which gives rise to a type of greediness which results in a wicked type of mischievousness. Bakasura (stork demon) - Cunning duplicity, deceptiveness and false types of behavior. Aghasura (the snake demon) - Cruelty and violence. Brahma-vimohana Pastime (Lord Brahma steals the cowherd boys and calves) - mundane activities and speculative scholasticism. Dhenukasura (the ass demon) - gross materialistic intelligence, ignorance of spiritual knowledge. Kaliya (chastising the Kaliya serpent) - brutality and treachery. Extinguishing the Forest Fire - Quarreling amongst Vaishnavas. Pralambasura (killing the Pralamba demon) - lusty inclinations; desire for personal gain and honor. Second Forest Fire - disturbance of religious principles and interference with religious people who are atheist. Brahmanas Performing Sacrifice - indifference toward Krishna caused by pride because of one's status (position) in varnasrama. Overcoming the Pride of Indra - demigod worship, and the tendency to think "I am Supreme." Nanda Maharaja Captured by Varuna - thinking that spiritual life can be enhanced by intoxication. Nanda Maharaja Swallowed by Vidyadhara (the snake) - rescuing the truth of Krishna consciousness from being swallowed by the impersonalists. Sankhacuda (killing the conch-shell demon and getting the jewel that was stolen by him) - proneness toward acquiring name and fame, and desire for sensuous enjoyment, under the plea of devotion. Aristasura (the bull demon) - pride arising from indulging in false religions invented by cheaters which causes neglect of devotional service (bhakti). Kesi (the horse demon) - The feeling that "I am a great devotee and spiritual master." Vyomasura (the demon in the sky) - associating with thieves and other rascals, and with people who put themselves forward as avataras.