Concise Bible Dictionary:

The word is pethen: it has been identified with the naja haje, a snake that has the power of expelling its deadly poison to some distance, which has caused the Dutch colonists at the Cape to call them the spitting snake. Its “cruel venom” is used symbolically to describe the wine of the wicked (Deut. 32:3333Their wine is the poison of dragons, and the cruel venom of asps. (Deuteronomy 32:33); compare. Rom. 3:1313Their throat is an open sepulchre; with their tongues they have used deceit; the poison of asps is under their lips: (Romans 3:13)), and the inward misery of those who are secretly wicked (Job 20:14,1614Yet his meat in his bowels is turned, it is the gall of asps within him. (Job 20:14)
16He shall suck the poison of asps: the viper's tongue shall slay him. (Job 20:16)
). In the millennium a child will play harmlessly at its hole (Isa. 11:88And the sucking child shall play on the hole of the asp, and the weaned child shall put his hand on the cockatrice' den. (Isaiah 11:8)).
Egyptian Cobra – Naja Haje

Strong’s Dictionary of Greek Words:

of uncertain derivation; a buckler (or round shield); used of a serpent (as coiling itself), probably the "asp"
KJV Usage: