When the Pharisees and Sadducees came to John the Baptist for baptism, John said,
But when he saw many of the Pharisees and Sadducees coming to his baptism, he said to them, “You brood of vipers! Who warned you to flee from the wrath to come?” (Matthew 3:7 ESV)
Jesus used the same language of the Scribes and Pharisees.
You serpents, you brood of vipers, how are you to escape being sentenced to hell? (Matthew 23:33 ESV) cf. 12:34)
The photo below shows the Palestinian Viper (behind tough plastic!) at the Hai Bar Animal and Nature Reserve, north of Eilat, Israel.
The sign at the Reserve gives some explanation about this poisonous viper.
A visit to Hai Bar is a wonderful experience.