The expecting model is the new face for PETA's campaign against SeaWorld. In the new ad, the blonde beauty shows off her growing baby bump as she lays naked in a bathtub with her arms and legs crossed to conceal her modesty.
"SeaWorld: Separating Babies and Mothers Since 1970," is splashed across the top of the ad, while "Boycott SeaWorld" is written at the bottom.
The 36-year-old stunner changed her views about the amusement park after she first watched the documentary "Blackfish," and shared her reaction with the organization.
"Being a mom and seeing Blackfish, it was extremely emotional," Miller tells PETA. "I think any mother knows the sense of protection and connection you have with your baby."
The animal rights organization likewise hopes this particular campaign will resonate with the public, because according to the nonprofit, "Orcas at SeaWorld cry out in grief after their children are taken from them and shipped off to other parks -- and that orcas at SeaWorld spend their lives in tiny concrete tanks that, to them, are the size of a bathtub."
Marisa isn't the only star lending her famous face to the cause -- Tommy Lee, Jessica Biel, and Steve-O are a few of the other celebs who have teamed up with PETA to "ask consumers to stay away from SeaWorld."
What do you think about the model's new ad? Tell toofab in the comment section below and see more stars who've srtripped for PETA in the gallery above!