Pretty clearly not an official foil job. The pattern isn't even CLOSE to anything that has ever been produced by Wizards of the Coast or Pokemon (and it looks like it's scratched), and even though it's hard to tell given the very strong, dark foil, the holo cards from that era still have the backgrounds of the non-holo versions. (Of course Base Set didn't have non-holo versions of holo cards, but Jungle and Fossil did, and Evolutions also re-used the Base Set backgrounds.) This Haunter rather clearly doesn't.
Someone clearly made this card foil. Pretty good job of it (aside from their poor choice of foil style), but obviously not official or usable in any capacity. It's the kind of thing whose value is purely subjective (since there is some effort involved), but most people probably won't care for. Wonder why they decided to use a Shadowless card for this. Not like it really makes any difference, but still.
