The Warner Bros. promo-machine is hard at work this week as its supernatural-western Jonah Hex arrives in theaters on Friday for a showdown with cowboy Woody and his Toy Story 3 posse. While smart money says Hex will most likely bite the dust, the film may have a shot in the dark in its star Megan Fox.

Fox, whose acting chops are often poo-pooed on by snobby film critics and fat chicks, goes the extra mile in Hex to play sexy, hatchet-wielding prostitute Leila. The 23-year-old stunner even went as far as to wear a corset cinched to give her an 18-inch waist.

She tells MTV News:

At the end of the day, when we would take [the corset] off, though, it would leave these deep grooves, these deep indents, from the boning in the corset and I would have it for like the whole next day.

The whole 24 hours I would be imprinted with the corset because it hurts your ribs.

We got it down to 18 inches, but in the action scenes we loosened it up [to 20-inches] because everyone was afraid I would pass out if we had it that tight.

Originally introduced in 1977 by DC Comics, Jonah Hex is a former Confederacy-officer-turned-outlaw-bounty-hunter looking to earn his freedom by helping the U.S. military stop a diabolical madman and his army of evil.

Jonah Hex costars Josh Brolin, John Malkovich, Will Arnett, Michael Shannon, David Jensen, Natacha Itzel, Brandi Coleman, Michael Fassbender, and Aidan Quinn.

Jimmy Hayward (Horton Hears a Who) directs with an assist from Francis Lawrence (I Am Legend).