A female traveller was recently banned from taking a large "emotional-support peacock" on board a United Airlines flight, it has emerged.
She had offered to buy the bird its own plane ticket, according to travel blog Live and Let Fly.
Nonetheless the airline refused to let the bird board at Newark airport in New Jersey, saying it did not meet guidelines due to its weight and size.
United says this was explained to the traveller before she arrived at Newark.
Pictures of the striking bird and its owner emerged via The Jet Set, a travel-based talk show.
The images show the animal perched on an airport baggage trolley, as fellow passengers gaze at it in shock.
Airlines have allowed some passengers with emotional or psychiatric problems to take therapy animals on board with them.
But the number of emotional support animals has been rising in recent years, sparking suggestions that people are abusing the system.
In 2014, a woman was escorted off a US Airways flight when her pig, named Hobie, defecated and squealed before the plane took off.