Numbers 21:8-9 ESV / 11
And the Lord said to Moses, “Make a fiery serpent and set it on a pole, and everyone who is bitten, when he sees it, shall live.” So Moses made a bronze serpent and set it on a pole. And if a serpent bit anyone, he would look at the bronze serpent and live.
Acts 28:3-5 ESV /
When Paul had gathered a bundle of sticks and put them on the fire, a viper came out because of the heat and fastened on his hand. When the native people saw the creature hanging from his hand, they said to one another, “No doubt this man is a murderer. Though he has escaped from the sea, Justice has not allowed him to live.” He, however, shook off the creature into the fire and suffered no harm.
Mark 16:18 ESV /
They will pick up serpents with their hands; and if they drink any deadly poison, it will not hurt them; they will lay their hands on the sick, and they will recover.”
Luke 10:19 ESV
Behold, I have given you authority to tread on serpents and scorpions, and over all the power of the enemy, and nothing shall hurt you.
Exodus 7:8-13 ESV
Then the Lord said to Moses and Aaron, “When Pharaoh says to you, ‘Prove yourselves by working a miracle,’ then you shall say to Aaron, ‘Take your staff and cast it down before Pharaoh, that it may become a serpent.’” So Moses and Aaron went to Pharaoh and did just as the Lord commanded. Aaron cast down his staff before Pharaoh and his servants, and it became a serpent. Then Pharaoh summoned the wise men and the sorcerers, and they, the magicians of Egypt, also did the same by their secret arts. For each man cast down his staff, and they became serpents. But Aaron’s staff swallowed up their staffs. ...
Personally, I think it was metaphorical, but hey, I could be wrong. Ouch!