What is the first legendary Pokemon you can get black and white 2?

In Pokémon Black 2 and White 2, the first legendary Pokémon you can encounter is Victini. You can obtain Victini in the special area known as the Victory Route by using the Liberty Pass, which allows access to the Liberty Garden where Victini resides. This event Pokémon is available early in the game, making it accessible soon after you start your journey.