The 2003 TMNT TV series was produced by 4Kids Entertainment, and Mirage Studios, which co-owned rights to the show, and animated by Dong Woo Animation. The series migrated to The CW4Kids in its final season after 4Kids's contract with Fox ended. Nickelodeon now owns the rights to this and any future Turtles series. Nickelodeon broadcast the series occasionally on their channel and Nicktoons normally during marathons for the TMNT series.