Sonic X is a Japanese anime television series created by TMS Entertainment and based on Sega's Sonic the Hedgehog video game series. Sonic X initially ran for 52 episodes, broadcast in Japan from April 6, 2003 to March 28, 2004; a further 26 were aired elsewhere from 2005 to 2006. The show's American localization was done by 4Kids Entertainment. The plot follows a boy named Chris and a group of anthropomorphic animals from another planet, including Sonic, Tails, Amy, and Cream, who repeatedly scuffle with Dr. Eggman and his robots over the Chaos Emeralds. The final story arc sees the friends return with Chris to their world, where they meet a plant-like creature named Cosmo and fight an army of robots called the Metarex in outer space. Sonic X received mixed reviews; writers criticized its localization and some characters, but were more generous toward its story and aesthetics. Merchandise included an edutainment game for the Leapster, a trading card game, and a comic book series. The phrase "gotta go fast", the title of the show's North American theme song, has been a Sonic catchphrase for over a decade.