Theatre of Blood (1973)

Edward Lionheart (Vincent Price) stars as an actor overlooked for a critics' acting award, despite producing a season of Shakespeare plays. After confronting the Critics' Circle, an attempted suicidal dive into the Thames results in Lionheart being rescued by your typical paraffin/meths/turps swigging tramps. Lionheart then (presumed dead) exacts his grizzly, and quite amusing revenge on the critics who denied him his finest hour.