As nouns the difference between vampire and siren
is that
vampire is a mythological undead creature said to feed on the blood of the living while
siren is (
original sense) One of a group of nymphs who lured mariners to their death on the rocks.
As a verb siren is
to make a noise with, or as if with, a siren.
As an adjective siren is
relating to or like a siren.