[HairOfTheDog]

They smell like orcs...

But I have never smelled an orc.

[Argh]

Be grateful.

[Argh]

I shouldn't be so flip, sorry. Orcs smell like a mixture of ammonia, skunk, sweat, and vomit. Which is why Tolkien never got too specific about it.

Add some really pungent sulphurousness and viola, er, voilà, balrog!