In my reviews of Batman: The Brave and the Bold (here and here), I'd noted that while the show is aimed at younger audiences, it is also aimed straight at the hearts of older fans—and I mean older—who are fanboys of the Silver Age era of swashbuckling Batman. The pre-credits sequence of last Saturday's episode, which is usually a short self-contained story where Batman teams up with a lesser-known DC hero, constructs it as a classic Space Ghost short instead, with Batman as the guest star.
No, sorry, college kids and potheads, it's not the talk show version of Space Ghost voiced by George Lowe. This Space Ghost is voiced by the original voice of Space Ghost, Gary Owens.
Batman: The Brave and the Bold is currently on its third season, but Cartoon Network put it on hiatus after just four episodes. New episodes, such as this one ("Bold Beginnings"), is still being released weekly through iTunes, so fans will have to watch it that way for the time being.