Revelation 9:19 KJV
For their power is in their mouth, and in their tails: for their tails were like unto serpents, and had heads, and with them they do hurt.
Revelation 9:17–21 KJV Chapter Context
17
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.
18
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.
19
For their power is in their mouth, and in their tails: for their tails were like unto serpents, and had heads, and with them they do hurt.
20
And the rest of the men which were not killed by these plagues yet repented not of the works of their hands, that they should not worship devils, and idols of gold, and silver, and brass, and stone, and of wood: which neither can see, nor hear, nor walk:
21
Neither repented they of their murders, nor of their sorceries, nor of their fornication, nor of their thefts.