These first two cards came within video games (Digimon World 1 and Digimon Digital Card Battle).
This rare MetalGreymon card seems to only appear around the U.K. You can tell it apart from the video game promo because there is no serial number on this card. The theory with the most credibility I’ve heard is this card was distributed to comic shops in the U.K. to promote Digimon (I’ve heard this from multiple unrelated sources).
This last one was from Universal Studios given out for a Digimon Weekend promotion.
