Demons killed by Sri Krishna
Putana was a demoness sent by Kamsa to Kill Lord Krishna. Putana disguises as a young, beautiful woman and tries to kill the Krishna by breast-feeding poisoned milk; however Krishna sucks her milk as well as her life via her breast.
Who was Putana in her previous birth?
Putana in past life was the daughter of King Bali , and she was known as Ratnamala. When Bhagawan Vamana went to during Yagna, that time after seeing Bhagawan Vamana as a dwarf, she thought that what if she would have a child similar to Bhagawan Vamana, to whom she can breastfeed”
Lord Vamana came to know about her desire and due to the same she was born as Putana and breastfed to Lord Krishna
Trinavarta (तृणावर्त) is an asura sent by Kamsa to kill Krishna. He had the power to form whirlwind.
दैत्यो नाम्ना तृणावर्त: कंसभृत्य: प्रणोदित: ।
चक्रवातस्वरूपेण जहारासीनमर्भकम् ।।
Who was Trinavarta in his previous birth?
Trinavarta (तृणावर्त) was previously a Pandya king named Sahasraksha (सहस्राक्ष) . He was engaged in activities with his queens on bank of a river Narmada .
Sage Durvasa was going along the same route , but the king did not offered sage the salutation. Durvasa rishi got angry by his act and cursed him – “Please become a demon”. King realising the same fell on to the feet’s of rishi.
Rishi Durvasa said to him – “You will be liberated by lord Krishna”
Vatsasura (वत्सासुर) is a demon sent by King Kamsa, which took form of a young calf and got mixed with the cow herd of Lord Krishna. He wanted to kill Krishna and Balarama, but was killed by Krishna.
Bakasura (बकासुर) is the crane asura killed by the Hindu god Krishna. He was sent by Kasma to kill Krishna.
स वै बको नाम महानसुरो बकरूपधृक् ।
आगत्य सहसा कृष्णं तीक्ष्णतुण्डोऽग्रसद् बली ।।
That great-bodied demon was named Bakasura. He had assumed the body of a crane with a very sharp beak. Having come there, he immediately swallowed Krishna.
Krishna captured the demon by the two halves of the beak, and very easily bifurcated him, as a child splits a blade of vīraṇa grass.
Aghasura (अघासुर) is an asura sent by Kamsa. He was one of Kamsa’s general, and the younger brother of the demoness Putana and Bakasura.
दृष्ट्वार्भकान् कृष्णमुखानघासुर: कंसानुशिष्ट: स बकीबकानुज: ।
He assumed the form of the 8-mile-long serpent, disguising his open mouth against a mountain.
Krishna entered the serpent upon his arrival and then increased the size of his own body. In response, the demon too extended his own body’s size, but started suffocating as Krishna was expanding more faster than him, causing his eyes to pop out.
The demon’s life force, however could not pass through any outlet, and therefore burst out through the top of his head killing the Aghasura.