vampires feed on human or animal blood, for monsters it would depend on the kind of monster you mean, a gilla monster eats lizards and birds, monsters created by humans imagination, eat humans or whatever their creator can think of, a chupacabra would be feeding on blood of goats.
A human who eats other humans is called a cannibal.
Humans, especially the French.etc.
Cookie monster like cookie! Om nom nom nom nom!
Kill the Monster Before It Eats Baby was created in 1996.
No. There are no monster plants that eat humans.
a monster that comes from the city dumpster and eats your family
Cookie monster 
snakes, humans, hawks, cats, there are a large variety of animals that eat birds.
Sharks are predators, they will eat anything smaller than them, clown fish to humans.
no, it eats antelope and such....
42.