And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God, Saying to the sixth angel who had the trumpet, Loose the four angels who are bound in the great river Euphrates. And the four angels were loosed, who were prepared for an hour, and a day, and a month, and a year, to slay the third part of men.

And the number of the army of the horsemen were two hundred thousand thousand: and I heard the number of them. And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone.

By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths. For their power is in their mouth, and in their tails: for their tails were like unto serpents, with heads, and with them they do hurt.

And the rest of the men who were not killed by these plagues yet repented not of the works of their hands, that they should not worship demons, and idols of gold, and silver, and bronze, and stone, and of wood: which neither can see, nor hear, nor walk: Neither repented they of their murders, nor of their sorceries, nor of their fornication, nor of their thefts. (Revelation 9:13-21)