Megan Fox/WMG

Megan Fox is an Active.
For clarification, Actives are people (volunteers) whose minds have been wiped and who can be "imprinted" with any personality and hired out for jobs.
 * I don't know about the Active thing, but I always pegged her for a cyborg created to control the male race with her unreal hotness. And some women too...

Megan Fox did film scenes for the third film.

 * Prior to quitting the film series, she was spotted on the film's set with Bumblebee's car, thus making it possible she filmed scenes for the third film.
 * While it's true she WAS on the set, that was just for principal photography, she quit or got fired before filming began.

Megan Fox will be the next Marilyn Monroe.
Just think about it.
 * I think you mean Shannen Doherty.
 * Oh, shit. Which is worse?
 * Marilyn Monroe was concerned that people didn't take her seriously so she went to acting school. Megan Fox has only yet to bitch about people not taking her seriously and then do more roles that nobody can take her seriously in. When Megan decides to go to acting school, then maybe this will work.

Megan Fox produces a pheremone that makes 30% of the population violently hate her
It explains why she's The Scrappy despite only being a mediocre actress in a few movies that weren't good anyway.
 * This sounds oddly like what happened on Miranda. I am disturbed.