Revelation 9:16-18

Young's Literal Translation

¹⁶ and the number of the forces of the horsemen [is] two myriads of myriads, and I heard the number of them.

¹⁷ And thus I saw the horses in the vision, and those sitting upon them, having breastplates of fire, and jacinth, and brimstone; and the heads of the horses [are] as heads of lions, and out of their mouths proceedeth fire, and smoke, and brimstone;

¹⁸ by these three were the third of men killed, from the fire, and from the smoke, and from the brimstone, that is proceeding out of their mouth,