Read Revelation 9:19 Using Other Translations
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.
For the power of the horses is in their mouths and in their tails, for their tails are like serpents with heads, and by means of them they wound.
Their power was in their mouths and in their tails. For their tails had heads like snakes, with the power to injure people.