Think of it as Hot Coffee, but without all of the lawsuits and sex. Looks like some goofy Nintendo programmers slipped an Arwing fighter from Starfox into Ocarina of Time. A reader sent me this screen cap along with a link to the video. In it you can see Link spotting the spaceship.
Just in case you absolutely need to check this out for yourself, run out and buy a Gameshark and use this code to unlock the space-time anomaly.
http://www.kotaku.com/gaming/ocarina-of-time/unlock-an-starfox-ship-in-zelda-game-129130.php
Includes video as well on page.