I used to fold an origami unicorn design by Marc Kirschenbaum. I can't find any instructions on the Modern Internet, but I used to fold it out of gum-wrappers while sitting in class.

The unicorn from the film itself wasn't "true" origami, being a prop consisting of several pieces glued together, but it really popularized the idea of an origami unicorn and a number of the current designs were prompted by it.