A Poke Ball that's used for special events. Like for catching defeated Raid Bosses or Shadow PKMN in Pokémon Go, and for PKMN Shenanigans in other Pokémon games. Starting from Pokémon Ruby/Sapphire/Emerald. It has the same rate as a regular Poke Ball, making it useless against 5-Star Raid Bosses, but it looks cooler.
PKMN Trainer 1: Time to use this Premier Ball on this Heatran!
PKMN Trainer 2: Phht, That thing is useless against Legendary PKMN like that.
PKMN Trainer 1: Yeah right.
PKMN Trainer 1 uses the Premier Ball on the Heatran. Not very effective.
PKMN Trainer 1: Oh
PKMN Trainer 2: Told Ya.