"Is anyone here allergic to penguins?" the captain of Delta Flight 486 from Atlanta to New York asked passengers—including this writer—on Wednesday night. "No? Alright, we have a surprise for you."

"How would we even know if we were?" I asked the woman seated next to me in seat 33D.

"He can't be serious," she said, pausing briefly as she flipped through her copy of Sky Mall.

But sure enough, after the plane reached a cruising altitude of 30,000 feet and the seat-belt sign was turned off, a pair of penguins waddled down the aisle from first class.

"You can take pictures, but we ask that you don't touch them," the captain announced. The flight's 300-plus delighted passengers heeded the warning, snapping photos and videos with camera phones lighting the aisle as if it were a red carpet.

The foot-and-a-half tall penguins, Pete and Penny, ages 6 and 12, were en route to the New York premiere of "Frozen Planet," a new Discovery Channel documentary series narrated by Alec Baldwin. The screening, held Thursday at the Lincoln Center, was followed by a "polar-themed" party, hosted by Baldwin, Dustin Hoffman and Glenn Close, among other environmentally-conscious luminaries.

[ SLIDESHOW: Penguins attend 'Frozen Planet' premiere ]

Oddly enough, this is not the first time penguins were allowed to roam the cabin on a commercial flight. In fact, it happens fairly frequently, judging by videos uploaded to YouTube.

Just last month, three penguins on Southwest's Orlando-to-LaGuardia trek emerged from their kennels midflight, surprising passengers.

Last March, a world-traveling waddler from Sea World made an appearance on a Southwest flight to San Diego from San Francisco, where it attended a science convention.

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