Alpha Pokémon

Originally introduced in Pokémon Legends: Arceus, Alpha Pokémon make a return in Pokémon Legends: Z-A. After you have completed the special mission, A Big Ol' Bunnelby, where you face off against an Alpha Bunnelby, Alpha Pokémon will start to appear throughout the game

Like before, Alpha Pokémon are denoted by a special symbol on their status screen. Their size is also set to maximum so they will be bigger than standard Pokémon of the species.

Alpha Pokémon also come with 3 maximum IVs at random, and in a change from the previous game, they natively come with 252 HP EVs as standard. They also come with a move the Pokémon can typically only learn through using a TM already mastered as a Plus Move

Alpha Pokémon can be found frequently in the wild in multiple ways in addition to ones you encounter during the story and missions.

First, throughout Lumiose City there are certain spawns that are guaranteed to be an Alpha such as a Gourgeist in Wild Zone 15, a Abomasnow in Wild Zone 12 and so forth.
In addition to that, many but not all spawns throughout the city have a chance of being an Alpha Pokémon. This chance varies based on different circumstances and runs from a 5% chance to a 40% chance depending on species and location. These Pokémon have an increased level compared to the initial spawn of typically around 10 levels.