In a USA Today article talking about her character on “Lost,” which includes spoilers on the show, it says Michelle Rodriguez will play Tigress:
Gripe as she might about the roles she’s offered, Hollywood continues calling. She has two horror movies in the can (BloodRayne, due Jan. 6, and The Breed, due later in 2006) and has signed a deal with Marvel Comics’ Stan Lee to develop a film version of Conan the Barbarian comic book villainess Tigress.
The villainess Tigress is a DC Comics character, however. The Marvel Comics character is Tigra, a hero and a former Avenger. It’s unclear which one the newspaper is referring to.
UPDATE: Many of you have pointed out that the above story is correct, that the character is indeed The Tigress (aka Zephra) from the Conan series, which Marvel holds the rights to. You can find out more on the character here.
Source: USA Today