Wizards of the Coast's first-ever game had a cameo card in an early Magic: The Gathering expansion.
References to obscure things or inside jokes in Magic: The Gathering are pretty common. You only need one purple, flying hippo to prove that. But every so often a reference comes out of left field that you really need to know the whole history of Wizards of the Coast to really get. Which brings up to Homelands, a 1995 expansion.
By 1995, Magic was quickly expanding after finding rapid popularity in its first few years. But that also meant that everything else at Wizards was being overshadowed. One of these things was The Primal Order, a roleplaying game supplement based on gods and religion that was designed to be integrated into any game. Whether it be Dungeons and Dragons, Warhammer, or Runequest, The Primal Order could be fitted to any of these sort of like how Pizza Hut buildings from the 80s and 90s can be refitted nowadays for anything from funeral homes to H&R Blocks.
TPO was also the first published work by Wizards and was spearheaded by Peter Adkinson. The first one came out in 1992, and after a few supplements, it was reissued in 1995. However, by this time, Magic and other entities were quickly taking over the core of Wizards business, with future games, like Pokemon, just on the horizon.
So back to Homelands. In that expansion, Primal Order was the name of a card. Take a look:
As noted by Mark Rosewater, the name was a direct reference to the game supplement. However, following the card, things went on a downturn for The Primal Order. They actually had 6 more supplements planned, which would have taken them through the rest of the 90s, (Including the spooky sounding The Military Order, The Economic Order, The Governmental Order and The Underworld Order) but two major things happened.
One, like we said, Magic took off and Wizards focused more on card games. And two, the capsystem method being used by TPO was actually found to be infringing on a copyright.
So, after 1995, that was the end of it. And when Wizards was bought out by Hasbro in 2001, TPO didn't go with it, staying with Adkinson instead.
And while it may come back some day, considering the litigation, it may stay in the dark and be relegated to only being sold on Ebay.