Bhagavad Gita Chapter 10, Verse 28

आयुधानामहं वज्रं धेनूनामस्मि कामधुक् | प्रजनश्चास्मि कन्दर्पः सर्पाणामस्मि वासुकिः ||

āyudhānām ahaṁ vajraṁ dhenūnām asmi kāmadhuk prajanas̆ cāsmi kandarpaḥ sarpāṇām asmi vāsukiḥ

Among weapons, I am the thunderbolt; among cows, I am Kamadhenu; among causes for procreation, I am Kama; and among serpents, I am Vasuki.

Krishna continues enumerating manifestations in various categories. 'Āyudhānām ahaṁ vajram'—among weapons, I am the thunderbolt. The thunderbolt (vajra) is Indra's weapon, the most powerful. 'Dhenūnām asmi kāmadhuk'—among cows, I am Kamadhenu, the wish-fulfilling cow. 'Prajanas̆ cāsmi kandarpaḥ'—among causes for procreation, I am Kama, the god of love. 'Sarpāṇām asmi vāsukiḥ'—among serpents, I am Vasuki, the king of serpents. This verse shows Krishna as the source of power (thunderbolt), abundance (Kamadhenu), creation (Kama), and transformation (Vasuki). Each represents the best or most powerful in its category.