Matthew 3:7

But seeing many of the Pharisees and Sadducees coming to be baptized, he said to them, Brood of vipers, who warned you to flee from the coming wrath?

Matthew 23:33

Serpents, brood of vipers! how can ye escape the punishment of hell?

Romans 3:13

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

James 3:8

but the tongue can no man tame; it is a restless 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 practised deceit. The poison of asps is under their lips.
James 3:8
but the tongue can no man tame; it is a restless evil, full of deadly poison.