Why: Many years ago, before anybody lived in the Northwest, there lived a very happy creature called a Wheedle. He was big, fat, and had a very large nose. But his peaceful life was disturbed by the sound of whistling from the happy people building Seattle. This made the Wheedle grouchy. So he stole their tools, but that didn't work. He tried to scare them, but that didn't work. He moved to the top of Mount Rainier, but that didn't work. He gathered up all the clouds in a bag, climbed to the roof of the Space Needle, and made it rain day and night in Seattle, and that did work. You see, it's not easy to whistle when your lips get all wet. So the people of Seattle sewed a giant pair of earmuffs so the Wheedle wouldn't hear their whistling. And the Wheedle folded the clouds into a pillow and fell asleep so soundly that his red nose started blinking. And that is why everybody thinks it rains a lot in Seattle, and why there's a blinking red light atop the Space Needle.
Impact: Wheedle on the Needle is Seattle's most beloved work of fiction, even beating out Frank Herbert's Dune. Immediately upon publication, Wheedlemania took hold; the Seattle Sonics even had a Wheedle as a mascot for their glory years of 1978–1985. Sadly, Penguin Books ruined the Wheedle, publishing a 2002 edition which redacted the environmental themes and de-Seattle-ized it. (If you come across a version without the Space Needle on the cover, feel free to set it ablaze.) But in a happy ending, Cosgrove won the rights back after a 15-year battle, and will publish a new Sasquatch Books edition in 2010. I'm in line already.
Personal Connection: Like every Seattleite of a certain age, I reflexively quote the book's closing quatrain:
On the Needle
I know just what
But if you look up
Late at night
His red nose blinking
I hope that at some point in the near future, I'll be able to walk onto the roof of the Needle and say hi.
Other Contenders: Edward Gorey's The Doubtful Guest, who shows no intention of going away; Dr. Seuss's The Lorax, who speaks for the trees; J. Otto Seibold and Vivian Walsh's Olive, the Other Reindeer, a dog who mishears her name in a critical Christmas carol lyric; the creatures visited by young Max in Maurice Sendak's Where the Wild Things Are; The Wolves in the Walls, whom Neil Gaiman and Dave McKean suggest should stay in those walls, or it's all over; Squammy, the lovable horror from the depths in Stan!'s The Littlest Shoggoth.