It was an udder catastrophe.

Cape May County Zoo’s famed “Jilly the Cow” head-butted and seriously injured a 14-year-old NJ teen as she posed for a photo with the mad cow, according to a lawsuit filed by the girl’s family.

The teen from Salem County, NJ, stopped to take a snap with the 10-year-old Holstein in the zoo’s petting area on Nov. 6, 2021 when “the cow suddenly, and without warning, violently and aggressively swung its head and struck [her] in the head,” the suit says.

The girl’s head snapped back and she fell to the ground, court papers claim.

The teen’s injuries required a trip to the hospital, physical therapy, surgery, and left the girl with “permanent scarring,” according to the suit.

The lawsuit alleges zoo officials failed to warn visitors the cow was dangerous or to put up “proper barriers” to protect visitors, according to the Nov. 3 filing Cape May Superior Court.

The zoo has posted a picture of the cow on Facebook, noting Jilly “loves eating hay, licking the goats, and licking zoo visitors!”

The lawsuit names the zoo, Middle Township NJ, the county’s zoological society and Cape May County as defendants.

The girl, who is now 16, continues to incur medical expenses, the lawsuit says.

“She did undergo treatment for injuries sustained after she was head-butted by the cow,” the family’s attorney, Victoria Kavanagh told The Post.

She declined further comment. Zoo officials declined comment.