Gordon, He-Man and the Masters of the Universe, its spin-off She-Ra: Princess of Power, and The Lone Ranger. He also did background work on G.I. Joe. He also worked for numerous other employers, including Ralph Bakshi and Don Bluth Productions, and attempted to find work at Marvel Comics and DC Comics, but was unsuccessful. During an animators strike in 1982, Timm found himself out of work and went back to Kmart for about half a year, before being hired by Don Bluth to help work on The Secret of NIMH. In 1987, he was hired by John Kricfalusi to do layouts for Mighty Mouse: The New Adventures, which Timm called "artistically and creatively the most fulfilling job that I'd had in the animation business" up to that point. He worked at DIC Entertainment on The Real Ghostbusters for one season in 1988, then joined Warner Bros. in 1989. At Warner, Timm worked on Tiny Toon Adventures. Timm was one of the creators and producers of the animated series based on various DC Comics superheroes, known as the DC Animated Universe. The DCAU has also named the "Timmverse" or "Diniverse", after both him and Paul Dini, a writer and producer. Along with his Tiny Toons partner Eric Radomski, Timm co-created and produced the Emmy Award-winning Batman: The Animated Series, which premiered on September 5, 1992, through which he and Dini co-created the character of Harley Quinn, and went on to co-create and produce Superman: The Animated Series (premiered in September 1996), The New Batman Adventures (premiered in September 1997), and Batman Beyond (premiered in January 1999), through which he and Dini co-created Terry McGinnis, the teenage Batman of the future, and his supporting cast. He also served as producer on the feature-length Batman Beyond: Return of the Joker (2000) before taking the helm as creator and producer of the animated version of Justice League, which debuted in November 2001; the series continued in the form of Justice League Unlimited in July 2004. Timm was also the producer and creator of Green Lantern: The Animated Series (premiered in November 2011). Along with Dini he created the animated series Freakazoid! (premiered in September 1995). Timm created virtually all the original character designs for Batman: The Animated Series himself, with the exceptions of Mr. Freeze and the Riddler, who were designed by Mike Mignola, and the characters Man-Bat and the Mad Hatter, who were