Bloodsucker

wiktionary

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blood +‎  sucker

(changeable lizard): Perhaps because of the reddish color of its neck.

etymonline

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bloodsucker (n.)

also blood-sucker, late 14c., of animals (leeches, mosquitoes, etc.), from blood (n.) + sucker (n.); in the figurative sense, of persons, it is attested from 1660s. Related: Bloodsucking.