I sketched this out while listening to a podcast. I did no clean-up on this image, just black sketch lines, followed by some color with an acrylic brush, followed by more acrylic brush in grayscale to create the impression of mountains, finished out with a gradient underneath it all.
There’s actually two backgrounds here: the top half is a mountain dropback, as if the Dragon Thing is lower down in the valley, while the bottom half is distant mountains, like the Dragon Thing is standing on another peak. I couldn’t decide which I liked better, so I did both!