Game Freak, Inc. (株式会社ゲームフリーク Kabushiki-gaisha Gēmu Furīku?) is a Japanese video game developer that currently creates games exclusively for Nintendo. It has developed the Pokémon series of role-playing games (RPGs) and several other games.
The company was founded on April 26, 1989 by Satoshi Tajiri, deriving its name from his self-published gaming magazine created by Tajiri and Ken Sugimori in the 1980s, which was written by Tajiri, and illustrated by Sugimori. One of Game Freak's first games was Famicom action/puzzle game Quinty, which was released in North America as Mendel Palace. Its most popular RPG series, Pokémon (ポケモン Pokemon?)—the romanized contraction of the Japanese brand Pocket Monsters (ポケットモンスター Poketto Monsutā?)—is published by Nintendo in Japan, North America and Europe.
Source: Wikipedia, "Game Freak", available under the CC-BY-SA License.