'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?