M.A.S.K. is an American cartoon that ran for a few years in the 80s. It had some killer intro music. Included in their promotional material were these stickers (sized at ~1.5×2.25in). They came in packs of seven like this. Many are cropped as they're meant to be pieced together with their respective counterparts for complete images. I find the odd framing really interesting. There are 126 here. I think there’re about 385 in total. They can be found on Etsy.
Feel free to use these scans for commercial purposes. Crediting me or this repository is appreciated.