Fangamer Sticker Series
Since they first opened up shop, Fangamer has been known to pack extra goodies in with the packages they mailed out, long before they sold exclsively official merchandise for notably many indie games, such as Stardew Valley and UNDERTALE, but later on, for big studios, such as Capcom and Konami. Some time back, they started including stickers as little bonuses with the packaging in the shape of the Fangamer logo, each featuring a unique piece of artwork from a studio or game they sold merch for. These stickers would be released as the "Fangamer Sticker Series".
Below if a list of all the stickers that are apart of the series that we managed to find at this time. Keep in mind, there were an early release a stickers that featured the same front design with a blank backside, before the series officially took off. These stickers, while identical in design and size, are notably not only for the blank back but for also not having as high of a quality sheen to them.