Bill Keveney

USA TODAY

A US Airways crew ordered a disruptive pig off a plane this week, adding a tasty new chapter to the annals of holiday travel and likely a million riffs on the phrase "when pigs fly."

A passenger on a US Airways flight leaving Connecticut's Bradley International Airport brought a pig on board Wednesday as an emotional-support animal.

The passenger and her pig left the flight after crewmembers decided the animal had to leave because of its disorderly behavior, Laura Masvidal, a spokeswoman for US Airways-parent American Airlines, said Friday.

A fellow passenger, University of Massachusetts professor Jonathan Skolnik, told the Associated Press he first thought the passenger was carrying a duffel bag, but an odor clarified the situation.

"It's no duffel bag but a rather stout PIG … on a leash," he wrote in an e-mail. "Am I dreaming?"

The woman, who sat next to Skolnik, tied the leash to the armrest, he said. He estimated that the pig weighed between 50 and 70 pounds, according to ABC News.

Skolnik said things got worse, which actually means better for late-night talk hosts drooling over the comedic mix of barnyard animals and air travel.

"The pig is incontinent," he told AP. The animal then started running back and forth, as its owner tried to control its behavior and clean up after the animal before eventually leaving the plane.

The U.S. Department of Transportation allows emotional-support animals on commercial flights, but only if they are not disruptive, Masvidal said.

Contributing: The Associated Press