pa·pa·raz·zo 
(pä′pə-rätsō)
(pä′pə-rätsō)n. pl. pa·pa·raz·zi (-sē)
A freelance photographer who doggedly pursues celebrities to take candid pictures for sale to magazines and newspapers.
[From Paparazzo, the surname of a character typifying such a photographer in the film La Dolce Vita (1960) by Federico Fellini.]