Earlier this month, the US brought in a new rule that allows airlines to ban all emotional support animals, meaning they are no longer required to board the likes of horses, pigs, peacocks and turkeys for psychological reasons. The new rule marks clearly the difference between trained support animals and emotional support animals, with owners now expected to check the latter into the cargo hold and pay any relevant airline fees. Alaska Airlines became the first to revise its service animal policy, in line with the US Department of Transportation's new rule, on December 29. "Alaska Airlines will no longer accept emotional support animals on its flights," a statement from the airline read. "Effective January 11, 2021, Alaska will only transport service dogs, which are specially trained to perform tasks for the benefit of a qualified individual with a disability." In the past, people carrying emotional support animals have been accused by critics of taking advantage of the system in order to transport their animals for free. The US DoT said that people taking unusual pets on flights as emotional support animals had "eroded the public trust in legitimate service animals". <b>Here, we round-up of the most memorable animals spotted travelling by air </b>–<b> or at least trying to:</b> Dexter the peacock was turned away from a United Airlines flight from Newark International Airport in 2018. At the time, an airline spokesperson said: "We explained this to the customer on three separate occasions before they arrived at the airport." The peacock's owner shared a photo of the bird at the airport on Instagram, writing: "Spent six hours trying to get on my flight to LA (after following all required protocol) Tomorrow my human friends are going to drive me cross country!" Writer Mark Essig first posted about Daniel the duck, and his owner Carla Fitzgerald, back in October 2016. The two flew from Milwaukee to Asheville via two American Airlines flights. "I heard a few maybe semi-critical mutterings, like, 'Now I've seen everything,' " Mark Essig told <i>The</i> <i>Washington Post</i> at the time. "But most everybody was delighted to have a duck on a plane. As they should be." In February this year, Ronica Froese, who has an incurable autoimmune disease, flew across the United States with her 18-month-old miniature service horse, Fred. The two flew on American Airlines from Grand Rapids, Michigan, to Ontario, California, on February 7 for a vacation — even connecting in Dallas along the way. As this was Fred's first time flying, Froese made sure that all bases were covered when it came to their journey together. "I have three fellow miniature service horse handlers that have all flown in the past who helped me prepare for the trip," Froese said at the time. "Fred is house-trained and trained to go potty every four to five hours for the flights; I made sure the flights were no longer than three hours for his comfort level." In January 2018, Jim Cunningham photographed a pig in the arms of its owner on his flight – although, he did not share where he was flying to or from. "There was an emotional support pig on my flight," Cunningham wrote on Twitter. "We have officially entered an episode of Black Mirror." Gizmo, an emotional support marmoset, landed his owner, Jason Ellis, in hot water back in August 2016. Ellis failed to inform the airline, Frontier Airlines, that Gizmo would be flying with him from Ohio to Las Vegas. When the miniature primate peeked out of his owner's shirt, Ellis didn't have the appropriate paperwork to hand. And when the two tried to take the return leg of their journey, Ellis found that they had been placed on Frontier’s no-fly list, denying them entry to the plane. The origins of the photo aren't clear, but it is wheeled out by popular travel Instagram account Passenger Shaming each Thanksgiving ... a turkey in airport security. The Instagram account highlights some of the terrible, and frankly revolting, behaviour from passengers on flights in its regular posts.