ἔχιδνα

Matthew 3:7 But when he saw many of the Pharisees and Sadducees come to his baptism, he said unto them, O generation of vipers, who hath warned you to flee from the wrath to come? Matthew 12:34 O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh. Matthew 23:33 Ye serpents, ye generation of vipers, how can ye escape the damnation of hell? Luke 3:7 Then said he to the multitude that came forth to be baptized of him, O generation of vipers, who hath warned you to flee from the wrath to come? Acts 28:3 And when Paul had gathered a bundle of sticks, and laid them on the fire, there came a viper out of the heat, and fastened on his hand.