Mega Evolution

Mega Evolution is an upcoming feature to the game.

In original game series, Mega Evolution was an additional evolution that allowed Pokémon to transform into stronger form of their final evolution stage during battle. It is unknown how Mega Evolution mechanic will be handled in Pokémon GO.

Mega Evolution was first mentioned in the Pokémon Presents on June, 2020. It will be released in Fall 2020.

Pokémon capable of Mega Evolution
The following Pokémon are capable of Mega Evolve in the main game series.

Trivia

 * Mega Lucario and Mega Mewtwo Y along with balloon of Mega Charizard X were featured in the key artwork for 4th Anniversary.