Revelation 9:19

For the power of the horses lay in their mouths and their tails; their tails were like snakes, and they had heads with which they injured people.

Ephesians 4:14

so that we may not be babies any longer, or like sailors tossed about and driven around by every wind of doctrine, by the trickery of men through their cunning in inventing new methods of error.

Revelation 9:10

they had tails like scorpions with stings in them, so in their tails their power lay to injure men for five months.

Treasury of Scripture Knowledge

Summary

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.

Bible References

In their tails

Revelation 9:10
they had tails like scorpions with stings in them, so in their tails their power lay to injure men for five months.
Ephesians 4:14
so that we may not be babies any longer, or like sailors tossed about and driven around by every wind of doctrine, by the trickery of men through their cunning in inventing new methods of error.