With such obscure questions I had to look at your profile to see whether you're a troll or not!
But no, it looks as if they're genuine!
Unless 'yellow snow' has got a meaning other than the obvious (and which Google doesn't seem to know about), I can only assume that the formula required is that for urea = (NH2)2CO
(Each of the 2s in that should, of course, be subscripts)
Snakebite?
Perhaps a type of lip (or body) piercing?
http://en.wikipedia.o..._%28disambiguation%29
Chris