Paper cranes are a popular and simple origami figure. There is an old Japanese legend that says anyone who folds 1000 paper cranes will be granted a wish by a crane. I personally don't know how this is supposed to work, whether you're supposed to find a real crane to ask, ask one of the paper ones, or whether a crane should appear before you in a puff of smoke upon completion of the 1000th paper bird, demanding that you make your wish because its time is valuable.
Attempting the feat remains quite popular however. There's even a technique called Renzuru for folding multiple cranes from a single sheet of paper. I know all of this because my friend Landon decided to embark on the spiritual journey of folding a thousand paper cranes, his goal being to complete the set in less than a year. He maintained that he'd do fine if he folded three a day. However he tended toward bursts of 50 or so, usually doing his renzuru-ing in the backseat of my car. I have so many paper cranes littering my car, I'm surprised that it hasn't yet taken flight. Maybe when Landon finishes his quest, the magic crane will appear in my backseat and give me his wish instead.