Some devotees
Srimad-Bhagavatam
SB Canto 3
In the Brahma-saṁhitā it is stated that the Lord is one Absolute, but He has ananta, or innumerable, forms. Advaitam acyutam anādim ananta-rūpam (Bs. 5.33). The Lord is the original form, but still He has multiforms. Those multiforms are manifested by Him transcendentally, according to the tastes of His multidevotees. It is understood that once Hanumān, the great devotee of Lord Rāmacandra, said that he knew that Nārāyaṇa, the husband of Lakṣmī, and Rāma, the husband of Sītā, are one and the same, and that there is no difference between Lakṣmī and Sītā, but as for himself, he liked the form of Lord Rāma. In a similar way, some devotees worship the original form of Kṛṣṇa. When we say "Kṛṣṇa" we refer to all forms of the Lord—not only Kṛṣṇa, but Rāma, Nṛsiṁha, Varāha, Nārāyaṇa, etc.