'Vipers' in the Bible

But when he saw many of the Pharisees and Sadducees coming for baptism, he exclaimed, "O vipers' brood, who has warned you to flee from the coming wrath?

O vipers' brood, how can you speak what is good when you are evil? For it is from the overflow of the heart that the mouth speaks.

O serpents, O vipers' brood, how are you to escape condemnation to Gehenna?

Accordingly John used to say to the crowds who came out to be baptized by him, "O vipers' brood, who has warned you to flee from the coming wrath?

"Their throats resemble an opened grave; with their tongues they have been talking deceitfully." "The venom of vipers lies hidden behind their lips."