We are aware of an issue in Pokémon Scarlet and Pokémon Violet in which players challenging the Tera Raid Battles for "Walking Wake" or "Iron Leaves" without downloading version 1.2.0 update data encounter an Egg instead of the intended Pokémon.
Currently, if you have captured one of these Eggs, you will be unable to capture the intended Pokémon. You also will be unable to participate in Tera Raid Battles with the Egg in your party, so please deposit it into your Pokémon Box.
Please be sure to update your software to the latest version when playing in Tera Raid Battles. We will provide more information in the future about how to resolve this issue for affected players. Thank you for your patience.