The Harpies were ancient Greek deities, half bird half woman creatures that stole food from the unwary:
The Harpies, who, like the Furies, were employed by the gods as instruments for the punishment of the guilty, were three female divinities, daughters of Tbaumas and Electra …
They were represented with the head of a fair -haired maiden and the body of a vulture, and were perpetually devoured by the pangs of insatiable hunger, which caused them to torment their victims by robbing them of their food; this they either devoured with great hungar, or defiled in such a manner as to render it unfit to be eaten.
-“The Myths and Legends of Ancient Greece and Rome”, by E. M. Berens