Kṛṣṇa's first expansion, second expansion, the third expansion. The third expansion is Mahā-Viṣṇu. So Mahā-Viṣṇu's potency is described in the Brahma-saṁhitā: yasyaika-niśvasita-kālam athāvalambya. Niśvasita-kāla means the breathing period. Just abiding by the breathing period of that Mahā-Viṣṇu, jīvanti loma-vilajā jagad-aṇḍa-nāthāḥ. Jagad-aṇḍa-nāthāḥ means the supreme creature, created, supreme created creature, Brahmā. Brahmā is the principal supreme creature in each, every universe. There are innumerable universes, and there are innumerable Brahmās also.
You will find in Caitanya-caritāmṛta, it is quoted from Śrīmad-Bhāgavatam that one sometimes... It is called līlā, pastimes, that Brahmā, when Kṛṣṇa was here on this planet, so Brahmā was very much proud that "Kṛṣṇa is now in the earthly planet, and this earthly planet is one of the innumerable planets under my control." Brahmā is the controller, is the primal, principal living entity in this universe, so he was little proud that "Kṛṣṇa is within my control." So therefore Kṛṣṇa, because He is Paramātmā, He knows everything, what one thinks, what one does. So Kṛṣṇa asked Brahmā to come and see Him. So Brahmā came. Brahmā came. His doorman informed Kṛṣṇa that... Doorman asked Brahmā, "Who are you, please?" "Now, you say Kṛṣṇa that I am Brahmā. I have come to see Him." So when the doorman informed Kṛṣṇa that in Dvārakā, when Kṛṣṇa was there as king, so Kṛṣṇa asked, "Oh, which Brahmā? Which Brahmā?" The doorman came back again and informed that "Which Brahmā you are?" So Brahmā became astonished: " 'Which Brahmā?' I am the Brahmā. I am the supreme creature within this universe, and 'Which Brahmā?' " He was surprised, and he said, "Tell Kṛṣṇa that four-headed Brahmā." Brahmā has four heads. So Kṛṣṇa called him, "All right, come on." So he came, and he offered his obeisances, and Brahmā asked Him, "Kṛṣṇa, my Lord, may I ask You some question?" "What is that?" "Your doorman asked me, 'Which Brahmā?' So does it mean there are other Brahmās also?" Kṛṣṇa said, "Yes, there are innumerable Brahmās. You are only four-headed. There are eight-headed, there are sixteen-headed, thirty-headed, sixty-four-headed, hundred-twenty-eight-headed, and millions of headed. So all right, I am calling them all." So Kṛṣṇa called all the Brahmās, and by His māyā, Brahmā could see them, but they could not see this four-headed Brahmā, and each of them came and offered obeisances to Kṛṣṇa, and they asked, "My Lord, what can I do for You? You have asked me?" "Yes. I have not seen you for so many times, so many days, so I have called you." So they came, thousands and millions of Brahmās came, and offered obeisances, and they went away. And this Brahmā, four-headed Brahmā, remained in the corner, "Oh, what is I am?" So this is Kṛṣṇa's creation.