A person who pursues someone or something with (ruthless) tenacity.

figurative. A ruthless and destructive person or thing; a bloodthirsty or savage person. Formerly as a strong term of abuse.

A person who or creature which seeks blood or bloodshed. Also in figurative context.

An inhuman monster, a cannibal.

Used to express ‘a blood-thirsty person’.

in the same sense.

a person who or creature which drinks blood; (figurative) a bloodthirsty person.

a person who enjoys scenes or descriptions of bloodshed and gory violence; (now) esp. a fan of films characterized by scenes of graphic violence…