LEECH

[noun] [C] - a fat worm which lives in wet places and fastens itself onto the bodies of humans and animals to take their bloodHe struggled through the swamp, tormented by mosquitoes and leeches.Biologists have learned that leeches secrete an anticoagulant to keep blood from clotting as they suck it from their victims.(figurative) The kids clung to any passing person like leeches, demanding attention.(disapproving) A leech is also a person who gives attention to someone over a long period in order to get their money or support.