'Vipers' in the Bible

But when he saw many Pharisees and Sadducees coming to his baptism, he said to them, "You offspring of vipers! Who warned you to flee from the coming wrath?

Offspring of vipers! How are you able to say anything good, since you are evil? For the mouth speaks from what fills the heart.

You snakes, you offspring of vipers! How will you escape being condemned to hell?