Community content is available under CC-BY-SA unless otherwise noted.
The Pokédex stores data for Pokémon when new species are captured. However, it has been successfully used on other creatures or objects, such as NPCs, who cannot be caught using Poké Balls.
A similar object called a BadgeDex appears in Mario The Boy Scout. It has information about different types of badges. There are currently 300,679 type of badges according to this Dex.
Another similar object called a YouTubeDex appears in SMG4: The Day SMG4 Posted Cringe. It looks like the Pokédex, but it has information about YouTubers.