Revelation 9:16-19

16and the number of the hosts of horse [was] twice ten thousand times ten thousand. I heard their number.

17And thus I saw the horses in the vision, and those that sat upon them, having breastplates of fire and jacinth and brimstone; and the heads of the horses [were] as heads of lions, and out of their mouths goes out fire and smoke and brimstone.

18By these three plagues were the third part of men killed, by the fire and the smoke and the brimstone which goes out of their mouths.

19For the power of the horses is in their mouth and in their tails: for their tails [are] like serpents, having heads, and with them they injure.