Kristen Johnston's ad Photo by: People for the Ethical Treatment of Animals (PETA)
PHOTO: Kristen Johnston Goes Naked for PETA
Kristen Johnston is speaking out against horse-drawn carriages – and stripping down in the process.

The 3rd Rock from the Sun star will appear in a new PETA ad campaign called "Don’t Get Taken for a Ride – Horse-Drawn Carriages Are Cruel." In her ad, Johnston, 41, appears naked on the back of a horse in a pose that recalls Lady Godiva.

"I was blown away by how these horses live, or actually I should say, don't live," the actress says in a statement. "I'd say to tourists who are considering coming to New York, there's so much amazing stuff about Manhattan ... Oh my God, just take a walk."

"And I hope within the next year that there are no more carriage horses," her statement continues.

The ads will debut Thursday in Central Park and appear on New York City taxis.

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