Shadow Ball is a special move in the Pokémon series, primarily used by ghost-type Pokémon. It is a dark, spherical energy attack that can deal damage to opponents while also having a chance to lower their special defense. This makes it a strategic choice in battles, as it can weaken the opponent's ability to withstand special attacks. The move was first introduced in Pokémon Generation II and has since become a staple in competitive play. Its effectiveness varies depending on the user's stats and the opponent's type, making it a versatile option in many battle scenarios.