Revelation 9:15-19

And the four angels, who had been prepared for the hour and day and month and year, were released, so that they would kill a third of mankind.

The number of the armies of the horsemen was two hundred million; I heard the number of them.

And this is how I saw in my vision the horses and those who sat on them: the riders had breastplates the color of fire, of hyacinth, and of brimstone; and the heads of the horses are like the heads of lions; and out of their mouths *came fire and smoke and brimstone.

A third of mankind was killed by these three plagues, by the fire, the smoke, and the brimstone which came out of their mouths.

For the power of the horses is in their mouths and in their tails; for their tails are like serpents and have heads, and with them they do harm.