barnacle
bedbug
blackmailer
extortioner
extortionist
freeloader
hanger-on
harpy
leech
lounge lizard
moocher
mosquito
murderer
parasite
predator
profiteer
racketeer
raptor
scrounge
scrounger
shakedown artist
shark
spiv
sponge
sponger
sucker
tick
vampire
vulture
wood tick
annelid
annelid worm
segmented worm
hirudo medicinalis
horse-leech
medicinal leech
Anglophile
bedfellow
bedlamite
blackleg
food-supply
pris
procuress
skinflint
softskin
spearhead
synergy
toolmaker