Jimmy Fallon, Justin Timberlake wrap up 'SNL' Christmas show and crack each other up

While "Saturday Night Live" host Jimmy Fallon and musical guest (and then some) Justin Timberlake were joined by several celebrity pals throughout "SNL's" highly-anticipated Christmas episode, the dynamic comedy duo didn't really need any help bringing big laughs to the audience — or even each other.

The pair proved that when they kicked off the show with a fresh spin on Timberlake's classic "Bring It On Down" musical skits. This time, rather than taking the action to "Veganville," "Liquorville," or "Homelessville," they stuck with the holiday theme and dressed up as a giant roll of wrapping paper and his gift-bag buddy for "Wrappinville."

Timberlake and Fallon then showed off their impersonation skills in a "Family Feud" skit that saw Fallon playing "The Big Bang Theory's" Jim Parsons and Timberlake playing Fallon. Bazinga!

When faced with the "Feud" question of what someone would do to be sexy, Fallon, delivering a particularly nerdy take on Parsons, suggested wearing a T-shirt bearing the likeness of Japanese director-animator Hayao Miyazaki. 

Meanwhile, Timberlake-as-Fallon had everyone cracking up (and had the real Fallon hiding under the panel with a case of the giggles) with his response to the same query, which was simply, "Be Justin Timberlake."

Musical legend Paul McCartney made a cameo during Fallon's monologue, but it was two other famous faces who appeared for the latest installment of "The Barry Gibb Talk Show" — Madonna and Barry Gibb himself.

Despite the A-list musical talent, the talk show skit stuck strictly to current events — well, beyond the always-catchy theme tune. But those interested in songs got their fix several times on Saturday night.

Fallon delivered his rendition of "Baby It's Cold Outside," complete with a clingy girlfriend twist.

And Timberlake took a break from cracking wise for his musical sets, including the laser-light treat, "Only When I Walk Away."