VGFacts

Peach with no legs:  http://www.joystiq.com/2014/12/11/biddin...sing-legs/
Samus with 2 cannons:  http://www.gamespot.com/articles/amiibo-...0-6423773/
Marth with 2 swords:  http://www.gamespot.com/articles/apparen...0-6424190/
Luigi with no hand: http://www.gamespot.com/articles/luigi-a...e=gamefaqs

I have to say, some of these defective amiibos are actually make the characters more interesting, especially Marth and Samus.
Shame that those extra features have no effect on gameplay.

There's also a weird positioned Link amiibo that looks like he's dancing and an upside-down Pikachu amiibo.
http://www.nintendolinked.com/amiibo-fig...cing-link/

Though the Pikachu amiibo doesn't seem to be defective.