(Isa. 14:29)
Sidney Sperry points out the serpent’s root, cockatrice (venomous viper), and fiery flying serpent are “all symbolic of evil to come upon her [Philistia].” (BMC, 245). Each of these represents a more deadly threat than the previous one mentioned. J. R. Dummelow identified Sargon (Assyrian king from 722 to 705 b.c.) and Sennacherib (Assyrian king from 705 to 681 b.c.) as the cockatrice and fiery serpent, “each one proving more terrible and formidable to the nations of Western Asia than his predecessor.”
(Hoyt W. Brewster, Jr., Isaiah Plain and Simple [Salt Lake City: Deseret Book Co., 1995], 149.)