The horses kill, not only with what pours out of their mouths, but also with their tails, which are like snakes with heads. The picture is of a snake connected by its tail to the horse’s rear, the snake’s head being the other end of the horse’s tail. It is the head that strikes at people and wounds them (the same verb is used in verse 10; see 2.11).

In English the use of the word serpents (Revised Standard Version, New Revised Standard Version, Revised English Bible, Translator’s New Testament, Phillips, Moffatt, New American Bible, Revised) evokes images of dragons rather than of snakes. (The American Heritage Dictionary does not list “snake” as one of the meanings of “serpent.”) It appears that a contemporary translation should use the word “snake”; but this is of no great importance.

An alternative translation model for this verse is:

• For it is the mouths and tails of the horses that have the power (or, ability) to hurt people. Their tails are like snakes with heads. They use these to hurt people.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .