Mahavishnu 

The first form to appear within the material creation is Mahavishnu. We hear from Scripture how this material world had its beginning.

Before the universal creation, Krsna expanded into the form of Mahavisnu, and from Mahavisnu’s breathing period came the creation and annihilation. Innumerable universes manifest when he exhales, not just one, but innumerable! When he inhales, they disappear. At that time all the souls go into a slumber until the next creation or exhalation period. Sometimes the slumber is called Nirvana or a domain without any material qualities. This is not to be confused with the brahmajyoti or spiritual effulgence.