Oh trust me, you'll know it when you see it. Ugly. Not that all of these fuckers aren't, but they're especially ugly. But you'll feel it in your head before you see it. It likes to trigger the fear mechanisms, so it can hit you while you're down.
They have fail safes between the air intake and the heart. Not to mention more of the small shits that are happy to throw themselves on something like that to save the big one.