"Rejoice not thou, whole Palestina, because the rod of him that smote thee is broken: for out of the serpent's root shall come forth a cockatrice, and his fruit shall be a fiery flying serpent." - Isaiah 14: 29
"For, behold, I will send serpents, cockatrices, among you, which will not be charmed, and they shall bite you, saith the Lord." - Jeremiah 8: 17
I just found two more passages that support the more mythical interpretation of the cockatrice that we all know and love. No mention of a chicken headed creature, but yet a fiery flying serpent!
I found an interesting website that theorizes that Pterosaurs may have existed during biblical times and might be a source for mythical creatures like the cockatrice and dragons. Interesting theory, difficult to prove but it definitely stirs the imagination.