Caitllyn Jenner                 Photo:USA Today

Retailers selling Caitlyn Jenner costumes for Halloween sparked a social media firestorm on Tuesday from critics who say the get-up insults transgender people and promotes stereotypes.

Jenner, a former Olympic gold medalist and reality TV star known as Bruce, came out as transgender this year and introduced herself in a Vanity Fair cover story that earned international attention.

A change.org petition launched on Monday is demanding that Spirit Halloween, a costume company with over 1,100 locations in the United States and Canada, stop producing and selling the costume, which includes a brunette wig, shiny white padded bustier and shorts resembling the outfit Jenner wore in the Vanity Fair cover photo. The petition had about 4,600 signatures by Tuesday evening.

"Trans is not a costume. Even though Caitlyn is a public figure and I could understand someone wanting to celebrate her as a hero and as a public figure, this could definitely take on a transphobic vibe," Addison Rose Vincent, an activist who started the petition, said in an interview.

The petition criticized the costume for making light of a community that faces serious challenges, including violence, suicide, homelessness and unemployment.

"To make a costume out of a marginalized identity reduces that person and community to a stereotype for privileged people to abuse," Vincent, 22, wrote in the petition.

A spokesman for Jenner said she had no comment at this time.

"We create a wide range of costumes that are often based on celebrities, public figures, heroes and superheroes," Lisa Barr, a spokeswoman for Spirit Halloween, said in a statement. "Caitlyn Jenner is all of the above and our Caitlyn-inspired costume reflects just that."

Barr said the costume would be available online and at Spirit Halloween stores by the end of September.

A similar costume already is available for pre-order on other retail websites, including Anytime Costumes and Wholesale Halloween Costumes. The costume set, which costs ksh5000 to ksh7500 on those sites, also includes a pageant sash that reads, "Call Me Caitlyn," the Vanity Fair cover headline.

"You can dress as the softer side of the popular Olympian," the Anytime Costumes description says.

"You probably won't break any Twitter records when you wear this outfit like Caitlyn did when she first made her account, but you'll be sure to get a few laughs out of your friends and the other guests at the get together," the description says.

(Reporting by Katie Reilly; Editing by Barbara Goldberg and Bill Trott)