Stone Cobra card
Even if the Stone Cobra figure didn't came with a card, this card exists. To get one you had to be a lucky Japanese kid. The card is a chase one that you could find in "D type" boxes. The chance to get it is not well known.
The card is a kind of rub sensitive card. When cold it represents a lion's head and when you rub it the Stone Cobra appears. The lion's head is in fact the seal that enclosed the cobra's soul. At the back are informations specific to the Stone Cobra.