Srimad-Bhagavatam: Canto 1 - Chapter 1 - Verse 20
कृतवान् किल कर्माणि सह रामेण केशव: ।अतिमर्त्यानि भगवान् गूढ: कपटमानुष: ॥ २० ॥
kṛtavān kila karmāṇisaha rāmeṇa keśavaḥatimartyāni bhagavāngūḍhaḥ kapaṭa-mānuṣaḥ
Lord Śrī Kṛṣṇa, the Personality of Godhead, along with Balarāma, played like a human being, and so masked He performed many superhuman acts.
The doctrines of anthropomorphism and zoomorphism are never applicable to Śrī Kṛṣṇa, or the Personality of Godhead. The theory that a man becomes God by dint of penance and austerities is very much rampant nowadays, especially in India. Since Lord Rāma, Lord Kṛṣṇa and Lord Caitanya Mahāprabhu were detected by the sages and saints to be the Personality of Godhead as indicated in revealed scriptures, many unscrupulous men have created their own incarnations. This process of concocting an incarnation of God has become an ordinary business, especially in Bengal. Any popular personality with a few traits of mystic powers will display some feat of jugglery and easily become an incarnation of Godhead by popular vote. Lord Śrī Kṛṣṇa was not that type of incarnation. He was actually the Personality of Godhead from the very beginning of His appearance. He appeared before His so-called mother as four-armed Viṣṇu. Then, at the request of the mother, He became like a human child and at once left her for another devotee at Gokula, where He was accepted as the son of Nanda Mahārāja and Yaśodā Mātā. Similarly, Śrī Baladeva, the counterpart of Lord Śrī Kṛṣṇa, was also considered a human child born of another wife of Śrī Vasudeva. In Bhagavad-gītā, the Lord says that His birth and deeds are transcendental and that anyone who is so fortunate as to know the transcendental nature of His birth and deeds will at once become liberated and eligible to return to the kingdom of God. So knowledge of the transcendental nature of the birth and deeds of Lord Śrī Kṛṣṇa is sufficient for liberation. In the Bhāgavatam, the transcendental nature of the Lord is described in nine cantos, and in the Tenth Canto His specific pastimes are taken up. All this becomes known as one’s reading of this literature progresses. It is important to note here, however, that the Lord exhibited His divinity even from the lap of His mother, that His deeds are all superhuman (He lifted Govardhana Hill at the age of seven), and that all these acts definitely prove Him to be actually the Supreme Personality of Godhead. Yet, due to His mystic covering, He was always accepted as an ordinary human child by His so-called father and mother and other relatives. Whenever some herculean task was performed by Him, the father and mother took it otherwise. And they remained satisfied with unflinching parental love for their son. As such, the sages of Naimiṣāraṇya describe Him as apparently resembling a human being, but actually He is the supreme almighty Personality of Godhead.