Chaotic dark spirit of Morgoth (Melkor)

"I am the Elder King: Melkor, first and mightiest of the Valar, who was before the world, and made it. The shadow of my purpose lies upon Arda, and all that is in it bends slowly and surely to my will."

I guess, this is that exactly moment when Melkor entered Arda for the first time, as you can see the landscape is still unformed, unshaped.