The teaser shows a cloaked, amphibious-looking being with red gauntlets.
The image was posted on DC Comics blog The Source on its newly updated website.
"Out this week, Justice League #7 serves as a prologue to the next big threat that will face the World's Greatest Superheroes, setting the stage for 'The Villain's Journey'," announced the publisher.
"Beginning in issue #9 with regular series artist Jim Lee's return to illustration duties, the story by Geoff Johns will introduce a mysterious new enemy for the Justice League. That's all we're saying for now."
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Lee has taken a break from the title following the conclusion of its first arc, with Gene Ha providing art for issue #7 and Carlos D'Anda on issue #8.
Justice League #9 will debut on May 16.