There were six of these issued by Burger King, and the all came inside a box with a plastic Pokeball that opened up with a small certificate of authenticity and the gold card inside a plastic case to protect the card. This is the only way they came from Burger King. Mewtwo, Jigglypuff, Charizard, Pikachu, Poliwhirl, and Togepi were the ones issued back in the mid 90s.
These were not in the kids meals. They were sold separately as a bonus promotion. They aren't worth much; you can check the prices they go for on Amazon.com. Best of luck with your auction!