Do acids like those seen in movies actually exist?

[Fanghur]

As a science student I almost feel foolish for even asking this, but do acids like those seen in movies such as Cube or Aliens actually exist outside of Hollywood? For those of you who haven't seen Cube, in one of the scenes, a 'prisoner' is sprayed in the face with some sort of extremely corrosive liquid, presumably an acid, that literally results in his head being practically hollowed out it is so corrosive. Within the span of several seconds or maybe a minute, the acid had completely eaten into his brain and reduced his entire head to little more than a hollow skull.

 

Now I'm 99.9% sure that an acid as powerful as this is a good example of Hollywood ludicrousy, but is there any, and I mean ANY chemical that could come anywhere close to having this sort of effect on a person? The blood of the Xenomorphs of the Alien series had the same general effect.

[OxygenBlue]

Nope, it wouldn't work that fast. HCl, HF and H2SO4 would burn skin quite fast, but not THAT fast.

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