(n.) One who soliloquizes; esp., one who monopolizes conversation in company.

Hamlet Roscius actor actress antagonist bad guy barnstormer character character actor character man character woman child actor diseur diseuse dramatizer feeder foil heavy histrio histrion ingenue juvenile matinee idol mime mimer mimic mummer pantomime pantomimist playactor player protean actor reciter soliloquist soliloquizer soubrette stage performer stage player stooge straight man stroller strolling player theatrical thespian trouper utility man villain