Matthew 3:7

And seeing many of the Pharisees and Sadducees coming to his baptism, he said unto them; O generations of vipers, who hath warned you to flee from the wrath to come?

Matthew 23:33

Ye serpents, generations of vipers, how can you escape from the judgment of hell?

Romans 3:13

Their throat is an open sepulchre; with their tongues they have used deceit; the poison of asps is under their lips.

James 3:8

but no one of men is able to tame the tongue; an incorrigible evil, full of deadly poison.

Treasury of Scripture Knowledge

Summary

Their poison is like the poison of a serpent: they are like the deaf adder that stoppeth her ear;

Bible References

Poison

Romans 3:13
Their throat is an open sepulchre; with their tongues they have used deceit; the poison of asps is under their lips.
James 3:8
but no one of men is able to tame the tongue; an incorrigible evil, full of deadly poison.