The name Pokémon is the portmanteau of the Japanese brand
Pocket Monsters. The term "Pokémon", in addition to referring to the
Pokémon franchise itself, also collectively refers to the 890 fictional species
that have made appearances in Pokémon media as of the release of the eighth
generation titles Pokémon Sword and Shield. "Pokémon" is identical in
the singular and plural, as is each individual species name; it is
grammatically correct to say "one Pokémon" and "many Pokémon",
as well as "one Pikachu" and "many Pikachu".