The Game Freak logo
Game Freak, Inc. (Japanese: 株式会社ゲームフリーク Kabushiki gaisha Game Freak), officially stylised as GAME FREAK inc. or less commonly as GAMEFREAK inc., is a Japanese game development company founded on April 26, 1989 by Satoshi Tajiri, Ken Sugimori, and Junichi Masuda, and the main company responsible for the Pulseman and Pokémon, along with other games.
You can read more about it in it's Bulbapedia page.