Alicia Silverstone
U.S. actress Alicia Silverstone arrives for the world premiere of British movie "Stormbreaker" at Leicester Square in London July 17, 2006. REUTERS/Paul Hackett

“Clueless” actress Alicia Silverstone was featured in the nude in a billboard ad by animal rights group PETA in Portland, Oregon for a campaign by the organization to discourage use of wool.

The billboard which was also seen in New York read: "I'd rather go naked than wear wool. Wear your own skin. Let animals keep theirs." The picture showed Silverstone turned slightly away from the viewer, holding a sheep mask near her exposed behind.

In a statement Monday, PETA said: “ Impatient workers have been caught punching, kicking, and stomping on sheep, some of whom die from the abuse. When the animals are no longer useful to the wool industry, they’re slaughtered. ”

Silverstone, in a video last year, was also heard saying she stopped using wool because sheep are cut during the shearing process.

"The biggest thing that people always say to me is, 'They just shear the sheep. They don't kill the sheep," the 41-year-old actor said, and stated emphatically that the process was quite violent. "The shearing isn't, like, 'Oh, let me just take your hair off because you need to give me your coat. It's not like that. It's like on the slaughterhouse floor, where there's a conveyer belt. It's going that fast. It's just so fast, the shearing process."

She added:"The [sheep are] cut. They're harmed. They get very seriously wounded. And there's no care for them when they're wounded. It's just move on to the next. These are not creatures to the people who are doing this. They're just objects."

The organization says Silverstone was a PETA supporter since her "Clueless" days and was among a list of celebrities who have bared it all to promote kinder wardrobe choices.

Meanwhile, residents of Portland had mixed opinions on the ad found at the corner of Northwest 21st Avenue and West Burnside Street , with one resident, Tiffany Harrison, telling Fox affiliate KPTV: “I support PETA, I do not like people wearing real animals. She didn’t have to be naked, but I think it is more of a statement, you know, just showing you can be natural without wearing fur,” she said, adding the billboard was not shocking for the city.

Latrent Harrison told FOX 12 he thought the ad was “natural” and supported “naturalism.” “I just hope the word gets out, and this is a good environment to display something like that, and I don’t find it offensive,” Harrison said.

Silverstone is among many celebrities who have posed nude for the organization’s various campaigns. Previously, billboards have featured celebrities like Penélope Cruz, Taraji P. Henson, Olivia Munn, Eva Mendes, Elisabetta Canalis and Pink going naked to support PETA’s drive to move away from animal products.

Another similar campaign against wool called #WoolFreeWinter featured actor Joaquin Phoenix in a series bus shelter ads in Boston which proclaimed “Cruelty Doesn’t Suit Me. Please Leave Wool Out of Your Wardrobe.” Phoenix was seen sporting a suit made of vegan wool.