Forum:A Pokemon card I once had

Ok so I've been scouring the Internet for months and I can't find any mention that this card even exists at all. My brother won it back when McDonald's (or Burger King I can't recall) was giving out pokeballs with gold Pokemon engraving things encased in clear plastic casings. Five of these pokeballs in the US had a card in them called Ancient Mew (I think.) We had this as well as two other rare-ish cards. Only trouble is my parents, not knowing the value of the card, sold all 300+ cards we had for $20 without telling us. I've been curious ever since of what I could've gotten for it.