SB 1.3 - Kumāras and Varāha
A list of incarnations follows. Note that the words first, second etc are only enumerating the avatāras and not indicating the exact chronology of their appearance.
(1) Garbhodakaśāyī Viṣṇu first appeared in the material world as the Kumāras. The four Kumāras, who being situated in a vow of celibacy, underwent severe austerities for realization of the Absolute Truth. There are different names of the creations in terms of the particular types of Brahmā. The Kumāras appeared in the Kaumāra creation of the material world to teach us bhakti and the process of Brahman realization. They are empowered incarnations. They are golden in complexion and were born from Brahmā.
(2) Appearing from the nostril of Brahmā, the supreme enjoyer of all sacrifices accepted the boar incarnation and lifted the earth from the nether regions of the universe (Rasātala) during the reign of Svāyambhuva Manu. He was black in color. The function of each incarnation is always extraordinary. The boar incarnation took the earth out of the Pluto’s region of filthy matter. Though appearing as a boar, the Lord is always transcendental. Varāha appeared again in a white form during Cākṣuṣa manvantara from water to lift the earth and pierced the demon Hiraṇyākṣa with His tusks. Hiraṇyākṣa was born from Diti who was the daughter of Dakṣa, who was the son of the Pracetas during the reign of Cākṣuṣa manu. So Varāha appeared twice in a day of Brahmā. During the first time, He simply lifted the earth from the ocean, and during the second advent, He killed Hiraṇyākṣa as well.