द्वौ भूतसर्गौ लोकेऽस्मिन् दैव आसुर एव च। दैवो विस्तरशः प्रोक्त आसुरं पार्थ मे श्रृणु ॥

dvau bhūta-sargau loke ’smin daiva āsura eva cha daivo vistaraśhaḥ prokta āsuraṁ pārtha me śhṛiṇu

Twofold is the animal creation in this world, the divine and the demoniacal: the divine hath been described at length: hear from Me, O Pârtha, the demoniacal.

In plain words: Krishna says there are two kinds of beings in this world, godly and demonic. He has already described the godly kind in detail, and now he will describe the demonic kind.