NEXT UP AT BAT

BETTER not leave the toilet seat up in the Batcave. In the highly anticipated new comicbook series “Dark Knight III: The Master Race,” Batman has apparently gone through some changes.

(Warning: Spoilers ahead.)

In the first issue, out Wednesday, it’s revealed that a woman has donned the famous cowl.

“I just think the suit looks a lot better on a girl,” writer-artist Frank Miller jokes to The Post.

The new Batman is Carrie Kelley, the former Robin introduced in Miller’s gritty bestselling 1986 series “The Dark Knight Returns.” Miller is cowriting “Dark Knight III” with veteran comic book scribe Brian Azzarello.

Miller says the idea to replace Bruce Wayne with a woman was hatched back in the 1980s. “Dick Grayson [the original male Robin] in my series made a good sidekick, but he never measured up. He went insane and became a bad guy,” Miller says. “Carrie is Batman’s equal.”

During a New York Comic Con appearance, Miller and Azzarello said the new sequel will “piss people off.” Miller says polarizing readers has always been in the DNA of “Dark Knight.”

“In the case of writing a story, the first thing you do is wake up the audience, and you do that by stimulating them with a pleasurable image or a shocking one. You have to get some kind of a reaction.”