The fiery serpents were deadly snakes sent among Israel in the wilderness as judgment for the people’s complaints. Their bite caused many deaths, but God provided healing through the bronze serpent Moses raised on a standard.
Those who had been bitten lived when they looked at the bronze serpent. Jesus used this event as an illustration of the lifting up of the Son of man. The bronze serpent was later preserved and destroyed by Hezekiah because it had become an object of idolatrous veneration.
The serpents appeared after Israel entered the sandy desert region extending from the mountains of Edom toward the Persian Gulf. The sources propose a venomous species but do not establish the identification with certainty.