Transformers, G.I. Joe, Strawberry Shortcake, He-Man, My Little Pony... all either toys first or simultaneously created as toys. Usuaslly a good giveaway is when Hasbro or Mattel is mysteriously the creator of the show.

Of course this isn't just a Western phenomenon, the video game/anime/movie/card game/merchandise extravaganza that is and always was Pokemon being probably the best single example.