Here's how you could have acquired it:
* 2000 World Championship Qualifier - This was the main way to obtain the card. It was given out to all participants in the 2000 World Championship Qualifier tournaments.
* Other Promos - There were some other limited distributions, possibly through Magic the Gathering events, promotions, or prizes, but those are extremely rare.
You can't find it in booster packs. If you see it for sale, it's likely someone is selling their promotional card.