After the series produced its 65th episode (the minimum number necessary for a TV series to be successfully syndicated), Fox Network executives ordered a second season of 20 more episodes that was later reduced to airing weekly on Saturday mornings.
The second season featured Robin more prominently and, as a result, was retitled "The Adventures of Batman & Robin" in the title credits; this run of episodes had two new opening sequences and ending credits. In total, Batman: The Animated Series reached 85 episodes before finishing its original run of episodes on September 15, 1995.
Batman: The Animated Series - Wikipedia, the free encyclopedia