To celebrate Pokémon Day 2024, Venusaur, Charizard, and Blastoise with the Mightiest Mark will be in 7-star Tera Raid Battles in Pokémon Scarlet and Violet.

Celebrate Pokémon Day with a Special Tera Raid Battle Event!

Face a Mighty Venusaur, Charizard, and Blastoise! Celebrate Pokémon Day by challenging Kanto’s fully evolved first partner Pokémon at black Tera Raid crystals in your Pokémon Scarlet or Pokémon Violet game.

The celebration begins when Ground–Tera Type Venusaur appears from Wednesday, February 28, 2024, at 00:00 UTC to Tuesday, March 5, 2024, at 23:59 UTC. Next, Steel–Tera Type Blastoise will be appearing from Wednesday, March 6, 2024, at 00:00 UTC to Tuesday, March 12, 2024, at 23:59 UTC. And finally, Dragon–Tera Type Charizard is returning to black crystal Tera Raid Battles from Wednesday, March 13, 2024, at 00:00 UTC to Sunday, March 17, 2024, at 23:59 UTC.

Venusaur, Charizard, and Blastoise cannot normally be encountered in the Paldea region. Be prepared—these Pokémon are formidable foes, and they’ve got the Mightiest Mark to prove it! Work together with your friends to topple these powerful Tera Pokémon!

The special Venusaur, Charizard, and Blastoise featured in this event can each be caught only once per save data. If you caught one of these Pokémon previously during a Tera Raid Battle event, you cannot catch it again. You can still participate in Tera Raid Battles against these Pokémon to obtain other rewards if you’ve already caught them.

The Venusaur, Charizard, and Blastoise appearing during this event may be featured in future events or become obtainable through other methods.

Event Schedule and Featured Pokémon

Ground–Tera Type Venusaur
• Wednesday, February 28, 2024, at 00:00 UTC to Tuesday, March 5, 2024, at 23:59 UTC
• 7-star Tera Raid Battles: Venusaur with the Mightiest Mark

Steel–Tera Type Blastoise
• Wednesday, March 6, 2024, at 00:00 UTC to Tuesday, March 12, 2024, at 23:59 UTC
• 7-star Tera Raid Battles: Blastoise with the Mightiest Mark

Dragon–Tera Type Charizard
• Wednesday, March 13, 2024, at 00:00 UTC to Sunday, March 17, 2024, at 23:59 UTC
• 7-star Tera Raid Battles: Charizard with the Mightiest Mark

What Is a Tera Raid Battle?

In a Tera Raid Battle, you’ll work together with three other Trainers to defeat a powerful Tera Pokémon before time runs out. The kinds of Pokémon encountered during Tera Raid Battle events will vary. Pokémon encountered in Tera Raid Battles may have a rare Tera Type.

Check the Poké Portal for more information about what Pokémon are appearing in Tera Raid Battles.

Information about Tera Raid Battle Events

• To participate in Tera Raid Battle events, please download the latest Poké Portal News by selecting Poké Portal from the X menu, then Mystery Gift, then Check Poké Portal News. You do not need a paid Nintendo Switch Online membership to receive the latest Poké Portal News.
• After completing certain postgame events, you’ll be able to find black Tera Raid crystals. However, players who haven’t completed these events may still participate in these Tera Raid Battles by joining other Trainers in multiplayer.
• A paid Nintendo Switch Online membership (sold separately) is required to participate in Tera Raid Battles with other Trainers online. Terms apply.
• Tera Raid Battle events will occur only in the Paldea region.

Source: https://sv-news.pokemon.co.jp/en/page/199.html