Cockatrice

A dragon's form, but with a rooster's head, sometimes described as having red to black eyes. Its look or breath is said to be poison. Cockatrice's powers of petrification are still effective after his death. -------------------------------------------------------------
"Supposedly there was a cockatrice found in the vault of a chapel during the time of Pope Leo the Fourth (847 to 855.). The breath of this cockatrice fouled the air, and caused many deaths in Rome."