Rihanna, Jon Hamm Helm Halloween 'Saturday Night Live' Episode

Singer re-teams with Andy Samberg's 'Shy Ronnie' for 'Ronnie & Clyde' skit.

This year's Halloween episode of "Saturday Night Live" went easy on the scares in favor of skits with a retro vibe. Jon Hamm, who hosted the same episode last year, mined his advertising executive alter ego from the midcentury drama "Mad Men," Don Draper, for laughs in his opening monologue. Leading an impromptu brainstorming session for product tag lines, Hamm suggested pushing diapers with the slogan, "Don't worry, little homie, we got your butt."

Musical guest Rihanna teamed up with Andy Samberg's timid alter ego Shy Ronnie once again for the digital short "Ronnie & Clyde," playing Prohibition-era bank robbers. Rihanna rocked a vampy, cropped suit jacket and fedora, busting up the joint as Clyde while Ronnie, awkwardly dressed in a flowing skirt and beret, bashfully hung by her side.

"Hands in the air, it's a stick up," she belted. "If you don't want to end up dead, you'll do anything Shy Ronnie says!" As a reserved robber, Ronnie is ineffective, mumbling his commands as the bank attendees look confused and Rihanna gets irritated. "No one in the back can hear you," she said. "Use your outside voice!" Rihanna tried to instill some confidence in her reticent partner and suggested he picture everyone naked. But then Ronnie got a little too excited and prompting Rihanna to proclaim, "Boner alert!" Rihanna ditched Ronnie after he shot himself in the foot, but having the floor to himself gave him a confidence boost, and he began to kick rhymes with gusto. "Ronnie, mother----er, and I'm back from the dead!" he spit, until Rihanna returned for more cash and a hunky hostage played by Hamm.

Hamm annoyed Bill Hader's Vincent Price as horny Senator John F. Kennedy, alongside Fred Armisen's randy impersonation of glitzy piano man Liberace, in a '60s Halloween special. Hamm also turned up in a skit about two bumbling '70s cops fighting crime with feathered hair.

The cast paid homage to the '80s sci-fi classic "Back to the Future" throughout the show, reenacting fake screen tests for the flick by some of the biggest stars of the era. Highlights included Jay Pharoah as an energetic Eddie Murphy, Kenan Thompson has a inarticulate Bill Cosby and Armisen as a brooding Prince.

Although Rihanna told MTV News on Thursday that she was "most looking forward to" acting in her digital short, the singer didn't short-change fans with her performances. She hit the stage first with hot pants, a crimson bra-top and wavy red locks for her flirty track "What's My Name?" The Barbadian-born diva gyrated and rocked some sultry moves on a set bathed in red light. She returned for "Only Girl in the World" in a completely red outfit with large bow tied in her hair. Throughout the song, Rihanna belted the chorus in a spotlight that obscured the rest of the band, giving the illusion that she was the only girl on the stage.

What did you think of this week's episode of "Saturday Night Live"? Let us know in the comments!