The official Pokémon website has announced that players of Pokémon Sword and Shield can encounter Eevee and its evolutions in Max Raid Battles from November 19th, 2021 until November 28th, 2021, at 3:59 p.m. PST.

Encounter Eevee and Its Evolutions in Max Raid Battles

You’ll find the Evolution Pokémon and friends in Pokémon Sword and Pokémon Shield, and you might encounter a Gigantamax Eevee or a Shiny Eevee.

You say you want an Evolution? Well, you're sure to get plenty of them during this month's Pokémon Sword and Pokémon Shield Max Raid Battle event—until November 28, 2021, at 3:59 p.m. PST, Eevee, Vaporeon, Jolteon, Flareon, Espeon, Umbreon, Leafeon, Glaceon, and Sylveon will be appearing more frequently in Pokémon Dens. The elusive Gigantamax Eevee will also be making an appearance, and you'll even have an increased chance of encountering a Shiny Eevee!

For an opportunity to encounter these Pokémon in a Max Raid Battle, you'll need to connect your Nintendo Switch system to the internet through Y-Comm or by selecting Mystery Gift in the X menu, then selecting Get the Wild Area News. After that, whenever you see a pillar of light shining from a Pokémon Den, you can walk up to the Pokémon Den and interact with it to start a Max Raid Battle with a Dynamax Pokémon. Usually, there'll be an extremely small possibility a Gigantamax Pokémon will appear instead of a Dynamax Pokémon, but during an event, certain Gigantamax Pokémon are more likely to appear. This event does not affect the Pokémon encountered within Dynamax Adventures.

Be sure to read our Pokémon Sword and Pokémon Shield Max Raid Battle Tips article for advice on how to topple these opponents. Don't wait, though—you don't want to miss out on the chance to add these Pokémon to your team!

Source: https://www.pokemon.com/us/pokemon-news/encounter-eevee-and-its-evolutions-in-max-raid-battles/