A 40-pound wolverine had to be sedated at Newark Liberty International Airport on Tuesday after it managed to chew through its metal cage.
Kasper was being shipped from a zoo in Norway to a conservation park in Alaska, but had to change planes and go through US Customs at Newark.
His handler Sarah Howard, a curator for the Alaska Wildlife Conservation Centre, said she noticed a hole in Kasper's cage, and said: "His head was sticking out."
So a new cage was sent from the Bronx Zoo, along with a vet. The cages were put face to face and Kasper was encouraged to walk into the new one.
Joseph Pentangelo, a spokesman for the Port Authority of New York, told the NY Times: "He balked. He did not want to go. He made it very clear."
So the vet administered a shot of ketamine, a form of tranquilliser.
Kasper spent the night in Terminal C before continuing his journey to the conservation centre, which sits on a 170-acre spread in the mountains about an hour southeast of Anchorage, in Portage.
According to ABC News, Mike Miller, executive director of the Alaskan conservation centre, said it was hoped Kasper would soon be joined by a mate, a female wolverine being sent to the centre from Sweden.
Wolverines resemble small bears but are actually part of the weasel family.
The wolverine is a solitary animal that has a reputation for ferocity and strength out of proportion to its size, with the documented ability to kill prey many times larger than itself.
The wolverine can be found primarily in northern Canada, the US state of Alaska, the Nordic countries of Europe, and throughout western Russia and Siberia.