Actress Olivia Munn is the latest celebrity to ditch her clothes and pose nude for PETA.  Munn sits nude, cross-legged, on a large billboard for PETA overlooking Los Angeles in an advertisement asking everyone to boycott the circus.

The Attack of the Show! host posed au naturel for the ad, which features a backdrop of elephants in their native environment alongside the words, “As Nature Intended, Let Elephants Be Free. Boycott the Circus.” The billboard, which was shot by top celebrity photographer Hama Sanders, is located at the corner of Wilshire Boulevard and Highland Avenue.

Munn feels especially passionate about this issue. In an exclusive PETA interview, she explains, “I had seen a video online about the mistreatment and abuse of these elephants at the Ringling Bros. circus event, and I was brought to tears.”

Munn, whose film credits include roles in Date Night and the upcoming Iron Man 2, was shocked by the video. “When you look at something like the circus, and everyone’s laughing and there’s color and there’s music and everything seems so great, but when you go right behind that door and [the animals are] in these crates all day long and then they’re getting shocked and beat just so they can get up and dance around on a ball,” she says. “It was just so sickening.”

Munn went on to ask her friends to use their social networking sites to help get the word out about circus animal cruelty.

Munn is calling on her fans to join her in boycotting the circus. “I think it’s really important,” she says, “that everyone at home, if you have a Twitter or MySpace or Facebook [page] or … your own blog, you have to get the message out because every extra person who hears about it―it just helps.”

Donate to The Elephant Sanctuary in Hohenwald, Tennessee that provides a retirement savanna for aging and crippled elephants from circuses and zoos across the country.