This thing is pretty cool. It's even an extremophile living near hydrothermal vents!https://www.wired.com/2015/02/absurd-cr ... oot-snail/
I present to you the scaly-foot snail, which has evolved a shell made of iron sulfide. I’ll repeat that: It builds a shell out of iron. On top of this, the squishy part that protrudes out of the shell, known as the foot, is covered with iron plates, making the scaly-foot snail more metal than Ozzy Osbourne wrapped in tin foil. And it’s all thanks to bacteria, which seem to be building the armor. No other animal on Earth can utilize iron this way. The thing is magnetic, for Pete’s sake.