(Video link) This 75-minute time lapse video shows Kim Jung Gi drawing an uber-complex street scene out of his head with no lay-in.
The stream-of-consciousness marker drawing covers two walls. Judging from his change of shirts, it took about three days. It includes flying elephants, motorcycles, and an assortment of farm animals, all drawn from interesting angles.
I got hooked and watched the whole thing, listening to Radiolab and Sidebar podcasts, since the video has no soundtrack. It might be better to watch it on the YouTube page to see the video full size.
Review of Kim Jung Gi's sketchbooks for sale
Muddy Colors post on Kim Jung Gi's books