I have heard about Kakabhusundi, who described the cycle of creation and recreation of the universe. Who was he? and how had he attain such knowledge?
Kakabhusundi was a crow and a great devotee of Shri Rama. He clears the confusion of Garuda regarding Shri Rama being God as mentioned in the Ramacharitmanas. He attained a vast knowledge because he had underwent many thousands of births but always remembered whatever he learned in his previous births and he was blessed by a sage. His life story is present in Ramacharitmanas which is briefly as below:
Bhusundi was born as a sudra in Ayodhya in the kali yuga of a previous kalpa. He was a devotee of Shiva and hypocritic to every other God. Affected by a famine he left Ayodhya and went to Ujjain. There he met a good Brahman who was devotee of Shiva. From him he learnt many things and worshiped Shiva daily. One day his guru tried to make him understand in every possible way that the sole reward of worshiping Shiva is the uninterrupted devotion to Rama.
But because he was haughty and hypocrite he became spiteful. One day while he was worshiping Shiva his guru entered the temple but he didn't rise and greet him out of pride. His guru being kind, didn't say anything. But Shiva got angry and cursed him to get thousands of repeated births in lower forms starting from a python as that is the consequence of offending one's guru. Hearing this curse he trembled in fear. But his guru pacified Shiva and asked for forgiving his disciple. So Shiva said, he would take thousands of birth due to the effect of the curse, but he will get rid of it quickly without feeling any suffering and agony of life and death. And he will also grow devoted to Shri Rama. After that he went through numerous births, but due to the blessing of Shiva he went through them without any pain and remembered his knowledge:
सिवँ राखी श्रुति नीति अरु मैं नहिं पावा क्लेस।
एहि बिधि धरेउँ बिबिध तनु ग्यान न गयउ खगेस।। [RCM - 7.109]
Later on he was born as a Brahmana and was devoted to Shri Rama. Once he went to sage Lomasa and asked him for discourse about God. Sage Lomasa narrated how jiva and Brahman are identical and not separate. He told Brahma is without any body, attributes and so on. Bhusundi didn't like it and argued with Lomasa. This made even the enlightened Lomasa irritated but he :
सुनु प्रभु बहुत अवग्या किएँ। उपज क्रोध ग्यानिन्ह के हिएँ।।
अति संघरषन जौं कर कोई। अनल प्रगट चंदन ते होई।।
बारंबार सकोप मुनि करइ निरुपन ग्यान।
मैं अपनें मन बैठ तब करउँ बिबिध अनुमान।।
Bhusundi argued too much in favor of saguna bhakti that Lomasa got angry and cursed Him thus:
पुनि पुनि सगुन पच्छ मैं रोपा। तब मुनि बोलेउ बचन सकोपा।।
मूढ़ परम सिख देउँ न मानसि। उत्तर प्रतिउत्तर बहु आनसि।।
सत्य बचन बिस्वास न करही। बायस इव सबही ते डरही।।
सठ स्वपच्छ तब हृदयँ बिसाला। सपदि होहि पच्छी चंडाला।। [RCM - 7.112]
Again and again I kept arguing for saguna worship. Then the sage became angry and said: "Fool, you are not giving your mind to the supreme lesson and only doing arguments and counter-arguments. You are not believing the true words and distrusting it just like a crow. You are haughty and your heart is filled with your own opinions. Therefore, you become a bird."
Bhusundi accepted the curse without any fear or humbleness. So when the sage found out that he was so devoted to Rama, he blessed him with knowledge and devotion of Shri Rama. And because it was in the body of a kaka (crow) he received that ultimate devotion to Shri Rama, he never gave up that body and hence he is known as Kakabhusundi. In that body of the crow beholding the Lord all his ignorance vanished:
ताते यह तन मोहि प्रिय भयउ राम पद नेह।
निज प्रभु दरसन पायउँ गए सकल संदेह।। [RCM - 7.114]