What’s that up in the sky? Usually it’s an airplane painted with an airline’s standard design, or livery, which serves as an important part of a company’s brand. But these lively, often one-off airline liveries use cartoon characters, animals and other imagery to perk up the skies.

Here are some of the fun airline liveries I found for a slide show on MSN Travel.

Alaska Airlines Salmon-Thrity-Salmon (Courtesy of Alaska Airlines)

Alaska Airlines’ theme planes honor Disneyland and colleges, universities and sports teams in the Northwest. Most popular, though, is the Salmon-Thirty-Salmon II livery, unveiled last October, which transforms a Boeing 737-800 into a 129-foot-long flying fish, complete with scales on the wings and salmon-pink lettering across the fuselage. A previous version of the flying salmon was painted onto a 737-400 in 2005 and repainted with the carrier’s traditional Eskimo livery in 2011.

Air New Zealand – ‘Hobbit’ plane

As part of a two-movie partnership with the producers of “The Hobbit: An Unexpected Journey” and “The Hobbit: There and Back Again,” Air New Zealand last year produced a “Hobbit”-themed in-flight safety video and unveiled the first of two “Hobbit”-themed liveries. The first, applied to a Boeing 777-300, is flying now between the United States, the United Kingdom and New Zealand, which stood in for Middle Earth in the movies. Another flying billboard, applied to a 777-200, will take flight when the second movie arrives in theaters.

Qantas – boxing kangaroo

A drawing of a kangaroo has been part of the Qantas Airlines livery for many years, and during the 2012 Summer Olympics, it donned a pair of boxing gloves to become a flying mascot for Australia’s Olympic teams. “The kangaroo is seen as a sporting image in Australia,” said Clark of TheDesignair.net, “and adding the boxing gloves sits well with the international image that Australia portrays of being a humorous society.”

Frontier Airlines – ‘spokesanimals’

Last April, Frontier Airlines announced that a wise-cracking parrot named — what else? — Polly beat out Chloe the chipmunk, Enrique the tree frog and 15 other cute contenders to win a new and coveted spot as a “spokesanimal” on the tail of a plane. Polly is in good company: 60 other animals, including Larry the lynx and Jack the rabbit, also have their pictures on Frontier Airlines planes.

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