Last weekend at the Pokémon World Championships, The Pokémon Company released a new trailer for Pokémon Scarlet & Violet - The Hidden Treasure of Area Zero part two The Indigo Disk.
One segment in the video showed off a new Tera Type. Nintendo has now taken to social media - teasing this nineteenth Tera Type:
Nintendo: "In The Hidden Treasure of Area Zero for #PokemonScarletViolet, a new Tera Type has been discovered—a nineteenth Tera Type. Something about it seems different from the eighteen Tera Types we’ve seen before. What is the truth behind this nineteenth Tera Type?"
Based on the trailer, it seems this 19th Terrestallisation is linked to all existing Tera Types. You can catch this moment in the above trailer around the 2-minute mark. Just keep in mind, this won't be made available until the second DLC is released.
This same trailer also revealed starters from previous generations would be returning and much more.