Update 9/1:

Marvel revealed the name of this mystery project at their Diamond Retailer Summit presentation in Baltimore tonight. It turns out that MU stands for "Monsters Unleashed."

Marvel didn't reveal any other new details about the project, but we can infer a lot from the title. The original Monsters Unleashed was a black-and-white anthology magazine from the 1970's that featured horror characters like Werewolf by Night, Man-Thing and Frankenstein's Monster. Presumably, those same characters will feature in this new project and the various artists named in the teasers below will draw individual stories written (or co-written) by Bunn.We'll keep you updated as Marvel reveals more about Monsters Unleashed.Marvel has revealed one more teaser ahead of tonight's reveal:Marvel has now released three more MU teasers. Whatever this mystery project is, it seems it'll pair writer Cullen Bunn with a number of different high-profile artists.None of these new teasers reveal anything more about the premise of MU or the characters involved, but at this point we only have to wait one more day to find out.The original story is below.

Marvel just released a cryptic teaser image for a new comic book project called "MU." True to form, this teaser doesn't reveal much more than the title and creative team.Whatever MU is, it'll feature Civil War artist Steve McNiven and current Uncanny X-Men writer Cullen Bunn. Interestingly, McNiven has top billing on the teaser, which could suggest he's co-writing the book with Bunn as well as drawing.As for the title, the obvious guess is that "MU" stands for "Marvel Universe." It could also stand for "Marvel United," which would make sense given that Marvel's books will be exploring a new status quo called "Divided We Stand" after Civil War II . Like 2010's Siege, MU could be the story that brings Marvel's fractured heroes back together to confront a common enemy.Whatever MU is, the teaser makes it clear that we'll find out more on Thursday, September 1. Be sure to check back then for more details on this mystery comic.

Jesse is a mild-mannered writer for IGN. Allow him to lend a machete to your intellectual thicket by following @jschedeen on Twitter , or Kicksplode on MyIGN