Cockatrice.
The cockatrice is frequently referred to in the Scriptures as the type of something evil. “The weaned child shall put his hand on the cockatrice’s den” (Isaiah xi. 8), meaning that the most noxious animal shall not hurt the most feeble of God’s creatures.
And Jeremiah viii. 17: “For behold, I will send serpents, cockatrices, among you which will not be charmed, and they shall bite you, saith the Lord.”
The cockatrice is a frequent emblem in heraldry, borne as a charge upon the shield and also as a supporter. To the mailed draconic form of the wyvern it had the hideous crested head with livid dangling wattles similar to the dunghill cock, its round glittering eyes dealing death; its barbed tongue and serpentine tail, with deadly sting, would no doubt render it a fearful object to behold, and terrific to its enemies. It is always borne in profile, the wings endorsed, or back to back, unless directed otherwise. The tail is frequently nowed, i.e., knotted.
Sable, a cockatrice or, combed and wattled gules.—Bothe.
Sable, a cockatrice, displayed argent, crested, membered and jelloped gules.—Baggine.
Jelloped, jowlopped, terms used to describe the comb or crest, and gills or wattles, when of a different tincture from the body. Beaked and membered, in similar manner, have reference to the beak and legs.
Basilisk, or Amphysian Cockatrice
The amphysian cockatrice or basilisk in heraldry exactly resembles the cockatrice, but having an additional head (like that of a dragon) at the end of its tail instead of a barb or sting.
“With complicated monsters’ head and tail
Scorpion and Asp and Amphisbœna dire.”
Milton.