Which of the following is not a real Pokémon?

Luminid is not a real Pokémon because it does not exist in the official Pokémon universe. The Pokémon franchise consists of various species, each with its unique characteristics, abilities, and evolutionary chains that have been officially recognized by the franchise developers and released in the respective games, trading cards, and other media. While Luminid may seem like a plausible Pokémon name, it has not been officially acknowledged or included in any official Pokémon material, making it a fan-made or nonexistent Pokémon species.