False Zelda is one of the bosses you encounter in The Subspace Emissary in Super Smash Bros. Brawl. She looks like Princess Zelda, only covered in black-purple mist. Unlike Zelda, she uses the Dark Cannon.
After Kirby left Zelda for a few seconds, Bowser turned her into a trophy and had Shadowbugs cover the trophy. Shortly after, False Zelda prepares to turn Link and Yoshi into trophies, but is stopped by Mario and Pit.
(NOTE: This only occurs if you save Zelda at the Midair Stadium. If you save Peach, False Zelda will be replaced by False Peach)
Later, False Zelda and False Peach appear to stop Meta Knight, Lucario, and Solid Snake from freeing the princesses.
Much like Zelda (only with glowing eyes and all purple).
False Zelda is one of the only bosses you don't beat in Boss Battle (the other 2 being False Peach & False Diddy Kong).