Surabhi Cow & Indra

The independent Lord Nityananda then walked with the devotees to Gadigachā village. When they arrived there, He smiled and said, “This island is named Godrumadvīpa. Surabhi stays here eternally. When Indra was overcome by Krsna’s illusory energy, he proudly flooded Gokula with rain. The Lord, however, carefully protected Gokula by lifting Govardhana mountain. Thus Indra’s pride was crushed, and he understood Kṛṣṇa’s identity. He therefore fell down at Kṛṣṇa’s lotus feet to mitigate his offense. The son of Nanda mercifully forgave Indra and pacified him.
“Still, Indra remained fearful, so he approached Surabhi and said, I cannot understand Kṛṣṇa’s pastimes, and for that reason I committed a great offense. I have heard that in Kali-yuga Vrajendra-suta will perform wonderful pastimes in Nadia. But I fear that I will again fall into illusion and commit offense. As you are Surabhi, a desire cow, you know everything. Kindly tell me what I should do now.’
“Surabhi answered, ‘Let us go to Navadvipa-dhāma and worship Nimai.’
“They came here and worshiped Lord Gauranga. Since the worship of Gauranga is easy, the results are easy to attain. By chanting Gauranga’s name, tears of love filled their eyes and they quickly attained Gauranga’s darsana.
“How extraordinary was His charming form! Gauranga was gently smiling and His voice was choked with love, for He was a reservoir of nectar. The Lord said, ‘I know your wish. I will soon appear in Nadia town. At that time you will serve Me, and the net of māyā will no longer catch you.’
“The Lord vanished, and Surabhi remained here beside a banyan tree, constantly serving Gauranga’s lotus feet. Therefore this place is called Godruma [go—cow; druma tree]. At this place the devotees’ desires are fulfilled. One who builds a cottage and worships here will easily become absorbed in Śrī Caitanya’s lotus feet.
(Sri Navadvipa-Dhama-Mahatmya, Chapter 8)

After instructing Indra, Lord Kṛṣṇa asked him to return to his kingdom in the heavenly planets and to remember always that he is never the supreme but is always subordinate to the Supreme Personality of Godhead. He also advised him to remain as King of heaven but to be careful of false pride.
After this, the transcendental surabhi cow who had come with Indra to see Kṛṣṇa offered her respectful obeisances unto Him and worshiped Him. The surabhi offered her prayer as follows: “My dear Lord Kṛṣṇa, You are the most powerful of all mystic yogīs because You are the soul of the complete universe, and only from You has all this cosmic manifestation taken place. Therefore, although Indra tried his best to kill my descendant cows in Vṛndāvana, they remained under Your shelter, and You have protected them all so well. We do not know anyone else as the Supreme, nor do we go to any other god or demigods for protection. Therefore, You are our Indra, You are the supreme father of the whole cosmic manifestation, and You are the protector and elevator of all the cows, brāhmaṇas, demigods and others who are pure devotees of Your Lordship. O Supersoul of the universe, let us bathe You with our milk, for You are our Indra. O Lord, You appear just to diminish the burden of impure activities on the earth.”
Then the surabhi cow bathed Kṛṣṇa with her milk, and Indra bathed Him with the water of the celestial Ganges through the trunk of his carrier elephant. After this, the surabhi cows and all the demigods and their mothers joined the heavenly king, Indra, in worshiping Lord Kṛṣṇa by bathing Him with Ganges water and the milk of the surabhis. Thus Govinda, Lord Kṛṣṇa, was pleased with all of them.
(Krsna Book Chapter 27: Prayers by Indra, the King of Heaven)