a person who remains in a place or attaches himself or herself to a group, another person, etc., although not wanted, esp. in the hope or expectation of personal gain.

noun

dependent , flunky * , follower , freeloader * , lackey * , leech * , nuisance , parasite , sponger * , sycophant , truckler , bloodsucker , leech , sponge , adherent , dangler , dependant , fawner , flunky , groupie , heeler , lackey , minion , satellite , scrounger , sponger , tagtail , toadeater , toady , vassal , votary