That's according to Isle of Wight zoo manager Kath Bright, who says Toga, a 3-month-old jackass penguin, was stolen Saturday from Amazon World on the Isle of Wight.
Bright says the bird, taken from a compound where he lived with his parents and four other penguins, will probably die of malnutrition if not urgently returned.
"Toga is very, very vulnerable. The penguin is still being fed by his parents and we don't believe it could survive more than five days," she told The Associated Press.
"The bird has already been missing for around three days and is likely to be severely dehydrated. If he isn't returned before Thursday, he is likely to become so ill that even intensive care treatment won't save him."
The brown-and-white penguin will bite if frightened and refuses to be fed by human hand, Bright said. Toga is too young to have yet had a gender confirmed but traditionally is referred to as a male, she added.
There was no sign of forced entry to the pen, but a thief would have been able to climb into the compound and carry Toga away, Bright said.
"We can't understand what may have been going through the thief's head, but we are worried someone decided a penguin would make the perfect Christmas gift," she added. "There has been a lot of attention because of the film 'March of the Penguins.' Perhaps someone saw the film and thought their wife or girlfriend would be thrilled to have one as a present."
The French movie was a box-office hit and has been credited with drawing tourists to penguin-spotting sites across the world.