The clay of the universe and above all attributes, this Krishna is Vasudeva When he becomes individual soul he is called Sankarshana. Next, he changes himself into Pradyumna and them into Aniruddha. Thus, the great Krishna, who has sprung from himself, divides himself in fourfold form.
विश्वावासं निर्गुणं वासुदेवं संकर्षणं जीवभूतं वदन्ति। माज्ञापयत्यात्मयोनिर्महात्मा॥