Mexican Desperados with Aqualungs.

The enemy of the Adunai and all else that is good and right in the universe.
They are foul and evil foes with no regard for honor.
Behind every cruel and pointless deed is an aqua-lunged sabateur perpetuating it.
Why do they hate us? It's unknown.
How can we stop them? I don't know.
But be wary of them, for they are among us, everywhere, disguised as normal people.
However, the sound of their hidden breathing aparatus can give them away,
the noise of gas inhaling and exhaling will let you know who they are.

note: these are not actual mexicans, but some race of cruel unknown creatures disguised as them. I like mexicans.