The 53rd element that occurs as a grey crystalline solid. It gives off a pretty, toxic, magenta-coloured vapour when heated, that should NOT be inhaled under any circumstance. It is one of two naturally-occurring halogens that crystallize at room temperature (the other being Astatine). Iodine's name comes from the Greek "Iodes", which means "violet-coloured".
If you've ever eaten a burger or a steak, and it's undercooked, you say "A little iodine and that thing could walk again!", implying that it's only a minor cut, and the animal could come back to life if iodine (a cut medicine) was applied.
Waiter: Here's your steak, sir.
Customer: *Cuts into the Steak, sees that it is raw.*
Waiter: Is everything OK?
Customer: Actually, no.
Waiter: What's wrong?
Customer: Weeeell, let's just say... A little iodine and that thing could walk again.
Waiter: Oh, no. Terribly sorry, sir.