I was just looking through an old folder of backdrops precisely sized for a monitor I used years ago and found this.
This is a picture of two of the stars of Parallax, back when it was something I was playing with as an idea for ultra-short sci-fi action cartoons that would be commercial bumpers. Well before Genndy's Star Wars show did that, fwiw.
Brush pencil on paper, Illustrator colors. The transparency on the windscreen had to be simulated manually because Illustrator didn't get transparency until 9 and this was done in 8.
Brush "pencil"? Brush PEN. Or maybe a brush dipped in actual ink, I dunno.