Magpie: A sort of small bird, known around the world for attending to, and often stealing away with, small shiny objects. The most common is the Eurasia magpie, Pica pica, which ranges from the Iberian peninsula down through southeast Asia; other species are known in China and Japan, including the delicate azure-winged magpie, Cyanopica cyanus, and the lovely antique blue Korean magpie, Pica pica sericea.
All magpies are members of the family Corvidae, a family of birds which also includes crows and ravens. Corvids are among the most intelligent of all birds, routinely beating out avians of such intellectual repute as parrots and macaws, particularly when it comes to having clever and rather juvenile senses of humor. Poe thought ravens were romantic; I think Poe was just never sober enough to get a good long look at them. We had enormous mountain ravens in Flagstaff that were basically raccoons with wings. They stole food, emptied dumpsters onto the surrounding sidewalk, had loud arguments at all hours of the day and night, and one flock of them used to sweep over the south campus parking lots at dawn and throw pine cones at cars until they set off the alarms, then sweep shrieking back into the woods where nobody could get at them.
Magpies, being smaller and somewhat daintier, are more crafty cat-burglars than teenage thugs. As mentioned, they seem to be fond of shiny objects, which often puts them at odds with the surrounding humans, who give economic value to same. The common view is that the males use these trinkets to decorate nesting sites, in order to impress the females; I'm not much of a biologist, so I don't know how true it is. I know that corvids in general show the same interest in almost anything that another creature is trying to keep them away from, not unlike domesticated rats and particularly enthusiastic dogs. I do know that magpies themselves are more decorative than they may at first appear -- their plumage is colorless under flat lighting, but in diffuse or refracted sunlight, the "black" feathers on their wings and tails flash blue and green, much like, and for the same optical reasons as, the thin surface of an oil slick.
As the birds range widely across Europe and Asia, so does the folklore surrounding them. Most cultures considered them clever, although some also considered them tricksters. I recall being told once that they were especially infamous among the Romans for stealing the shiny little white pebbles out of counting boards. It's probably apocryphal, but I always liked that image -- a determined little bird plucking number after number up and taking it home, to hoard calculations in its nest. The counting pebbles, of course, were called calculi, the diminutive of calx, stone, and their name eventually gave us what we call "calculus", originally "the calculus of infinitesimals", concerning the final summations of uncountably many unimaginably small quantities.
Magpies also have a strange connection to books. The size of type is traditionally measured in units called pica, which you may recall from the top of the article is the proper Latin name of the little birds. Pica is the original Latin name for the magpie itself, echoed in the modern French pie, and part of the modern English term, and it came to be applied to printing when people associated the stark black of type on white paper with the bird's plumage. In the modern system, familiar to all who use Microsoft Office, there are 12 points to the pica, and 6 pica to the inch.
Coincidentally, the Japanese adjective ピカピカ ("pikapika"), pronounced the same as the scientific name of the bird, is phonomimetic for the sparkle or twinkle of a glittery object, like gemstones or stars. The actual Japanese word for magpie is かささき ("kasasaki"), which has a kanji I've honestly never seen before, composed of pieces for "antique" and "bird"; another one for the azure-winged magpie in particular is 尾長 ("onaga"), whose characters literally say "long tail". The Mandarin word for magpie, 喜鵲 ("xǐque"), uses a different variation on the single-kanji Japanese version, prefaced with a hanzí that means "joyful", as the birds are held to bring good fortune.
Magpies are also tied into a legend prevalent in large chunks of east Asia, about a princess and a cowherd. The Japanese version of the story goes that Orihime, daughter of the Heavenly Emperor, had such unparalleled skill with the silk looms that the cloth she wove for her father was in demand all over the heavens. Tired of her continual and lonely work, she slipped off one day to bathe in the Heavenly River -- the band of stars we call the Milky Way -- and there met Kengyuu, a simple cowherd, with whom she fell in love. At first, her father saw her happiness and blessed the marriage, but once wed, the two had eyes for nothing but one another; she wove no more, and his cows roamed the heavens and the earth alike, untended. The Heavenly Emperor separated them in anger, but so great was Orihime's sorrow that he relented, and allowed that if both went back to their work for the year, they would be able to meet freely on the seventh day of the seventh month. They did as they were bid, but when the day arrived, they found themselves on opposite banks of the Heavenly River. Orihime sank down and cried, and her tears summoned a flock of magpies, who built a bridge of their wings so that she could cross to meet her husband.
In modern times, the seventh day of the seventh month (July 7th, as most places officially run on the Western calendar now, but celebrations can start anytime from early July to mid-August) is held as the holiday Tanabata, 七夕 "seventh evening". It's an interesting mix of Christmas, Valentine's Day, and summer festival; a big part of the tradition holds that Tanabata is a time for making wishes. Hopes and dreams for the next year are written on tanzaku papers, or small symbolic origami figurines folded, and tied to bamboo plants much as we would tie ornaments onto a Christmas tree, in the hopes that your particular wish will be granted as Orihime's was.