Actor Arnold Schwarzenegger will star in the upcoming action-comedy film 'Why We're Killing Gunther'. The 68-year-old will portray the titular character of 'Gunther', an elite assassin. The film will mark the directorial debut for Saturday Night Live's (SNL) Taran Killam. The film also stars 'How I Met Your Mother' actress Cobie Smulders and SNL actors Bobby Moynihan and Paul Brittain.