Revelation 9:19

For the power of the horses to do harm is in their mouths and also in their tails. Their tails are like serpents, for they have heads, and it is by means of them that they wound people.

Isaiah 9:15

The elderly and honored man, he is the head; and the prophet who teaches lies, he is the tail.

Ephesians 4:14

So then, we may no longer be children, tossed [like ships] to and fro between chance gusts of teaching and wavering with every changing wind of doctrine, [the prey of] the cunning and cleverness of unscrupulous men, [gamblers engaged] in every shifting form of trickery in inventing errors to mislead.

Revelation 9:10

They have tails like scorpions, and they have stings, and in their tails lies their ability to hurt men for [the] 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 have tails like scorpions, and they have stings, and in their tails lies their ability to hurt men for [the] five months.
Isaiah 9:15
The elderly and honored man, he is the head; and the prophet who teaches lies, he is the tail.
Ephesians 4:14
So then, we may no longer be children, tossed [like ships] to and fro between chance gusts of teaching and wavering with every changing wind of doctrine, [the prey of] the cunning and cleverness of unscrupulous men, [gamblers engaged] in every shifting form of trickery in inventing errors to mislead.