The Hey Arnold! CatDog Nickelodeon Basic Fun Keychain 957-0 is a vintage collectible from 1999. This original keychain features the popular characters from the Nickelodeon Animation Studio series, CatDog, in a multicolor design. Made of plastic, this keychain is a nostalgic piece for fans of the TV show Hey Arnold! and collectors of TV, movie, and video game-themed memorabilia. Manufactured by Basic Fun, this keychain represents a piece of 90s pop culture history.