All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
We have not come across any authentic texts about the description of the creation that Allah will create to fill the surplus space in Paradise.
We advise you not to be preoccupied by such questions that do not lead to doing good deeds. You should rather be concerned with what benefits you in your religion or your worldly affairs.
Allah knows best.