The Hebrew expression "saraph me'opheph" occurs twice in the Old Testament, and both times in Isaiah. Isaiah 14:29 refers to the "fiery flying serpent" and Isaiah 30:6 the term is usually understood as a reference to the sand-viper. Such interpretations imply that these creatures were semi-mythological. This article calls into question this interpretation, showing from contemporary data that these creatures may have been some kind of poisonous winged insect.