One of Pokemon Sword and Shield's most elusive Pokemon only appears when players complete a quest that is a perfect callback to Pokemon Diamond and Pearl. Traditionally, one of the hardest non-Legendary Pokemon to obtain is Spiritomb, a powerful Ghost/Dark-type Pokemon. The Pokemon typically only appears when players complete certain criteria, not all of which are very obvious. Usually players can only catch one of these Pokemon per game, so they're almost as rare as a Legendary Pokemon. Pokemon Sword and Shield's Crown Tundra DLC adds Spiritomb as a catchable Pokemon, but players will need to complete a specific task that ties directly to how the Pokemon first appeared in Pokemon Diamond and Pearl.
In the Ballimere Lake area of the Crown Tundra is a gravestone under a normal sized tree. If you interact with the tombstone, it will tell players to "Spread my Voice." Once players speak to 32 different trainers (the characters that appear when connected online) in the overworld, you can return to the gravestone and interact with it a second time. When it says "My voice has been heard," Spiritomb will appear and be an encounterable Pokemon to battle and capture.
So - why do you need to speak to 32 different trainers? Because that's how many online trainers you needed to speak to in order for Spiritomb to appear in Pokemon Diamond and Pearl. Those games required players to enter the Underground, an area where players could interact with each other when they used their DS Wireless Communication function.
This is only the third time that Spiritomb has been capturable in a Pokemon game (players could trade for Spiritomb from an NPC trainer in Pokemon Black and White, and it was only obtainable through Friend Safaris in Pokemon X and Y), so players should take advantage of the opportunity. It's also a great little callback to its original appearance using online functionality in Pokemon Diamond and Pearl, and a sure sign that Game Freak still looks back fondly on those games.
The Crown Tundra DLC is available now.