When I first started researching and collecting vintage cigarette/tobacco wolf cards over six years ago, this was one of the first cards I learned about. The 1900 Wills's Wild Animals of the World set is not really rare. There are maybe a dozen or so cards form the set listed on eBay at any given time. However I have NEVER found the Wolf card from the set available, anywhere, period. The "greenbacks" as they are commonly referred to feature a full color picture of an animal on front and the stylized back was an advertisement for the brand that depicted the brand logo and trademark. There is no text about the animal on front or even a checklist of the cards in the set on the back. Having at least the set checklist on the card backs was very typical for turn of the century non-sport tobacco sets. I only recently learned about the "blackbacks" playing card variations for the set. In addition to the different color of the logo on the back, each card front has a playing card (2 of Spades, 9 of Diamonds etc.) on the front. The cigarette manufacturer not only inserted collectible trading cards in the packs, but literally created probably the first collectible game card! (CGC) So after years of research, expanding my knowledge about vintage pre-war and traditional tobacco cards and sets, numerous emails to museum curators all over Europe and the National Library of Australia, and acquiring the #1 wolf card collection on the PSA registry I FINALLY found the first ever wolf card I starting looking for! This is my "holy grail' of my wolf card collection. As an added bonus I also picked up the much rarer playing card variation in amazing condition! Only collectors may know and appreciate the "thrill of the hunt" and the excitement and satisfaction you feel when you finally complete a set or get that one card you have been searching for. I have better condition and more rare/valuable wolf cards in my collection, but this is the one that started it all, this is the crown jewel of my wolf card collection!