Jimmy Fallon is always up for a challenge…
So he knew when the usually serious Kristen Stewart was set to appear on his show Tuesday to promote her new flick Camp X-Ray, he had to get extra goofy!
[ Photos: Kristen Stewart Wears Sexy Dress At Camp X-Ray Screening! ]
Cue a rousing game of Ring Around The Nosey - that even had stoic KStew cracking a huge smile!
Ch-ch-check out the silliness (below)!
OMG. Jimmy Fallon has been on a lot of fake TV shows in his time hosting The Tonight Show, but we haven't seen him break this much since Saturday Night Live!
[ Video: Zac Efron Dresses In Drag And Twerks With Jimmy Fallon ]
And it's all thanks to his co-star, the inimitable Carol Burnett!
Ch-ch-check out the video (above) to see the veteran funny lady show Jimmy a thing or two about staying in comedic character!
Also, she slaps him. A lot. It's pretty great.
Ew-Mazing! Get it?!
A LOT of major stars have loaned their voices to Jimmy Fallon's always-funny Ew! skits on The Tonight Show and now it's Will.I.Am's turn.
Of course, Will used his music making skillz to bust a few rhymes and beatz and tell a silly, yet irresistible story.
[ Related: Taylor Swift Goes Nerdy For Ew! ]
Who doesn't love a song with lyrics about Iggy Azalea's bodacious behind??! HA!
Ch-ch-check it out (above)!!!
Hands down! We have a winner!
This is the best parody of Taylor Swift's Shake It Off, which is already a perfect song as we all know!
Leave it to Jimmy Fallon's Tonight Show to feature a cover of said perfect song…with a twist!
[ Photos: Taylor Swift's Most Glamorous Red Carpet Moments! ]
In this video, The Roots' Questlove and Kirk Douglas make up the two-man Black Simon & Garfunkel group, and wow, their harmonies were incredible!
They make Shake It Off feel like it was written in the 1970s!
Watch the folksy cover (above)!!!
Now that summer is over and the leaves are changing colors as fast as Michael Clifford changes the hue of his locks, it's time for 5 Seconds of Summer to change their band name!
Because, like, it totally makes sense to - right??
[ Related: ICYMI: 5SOS Gifts Two Performances Of Their Singles! ]
5 Seconds of Fall The Aussie cuties made their debut on The Tonight Show Starring Jimmy Fallon last night and played a HIGHlarious game of #Hashtag with the late night host.
We can't listen to the original songs without thinking of these reworked lyrics now. LOLz!
Ch-ch-check out all the #FallSongs (above)!!
As the host of the season premiere of Saturday Night Live, we hope Chris Pratt knows how to play along!
Well, it looks like Jimmy Fallon is really testing his comedy improv skills with the ridicu-larious game of Word Sneak!
[ Video: Chris Pratt Tells Jimmy Fallon What He Stole From SNL ]
Ch-ch-check out the video (above) to see Chris and Jimmy get their jellyfish all over Patrick Ewing in a totally normal, not-weird-at-all conversation!
This isn't Chris Pratt's first time doing Saturday Night Live sketches? What a rip-off!
[ Video: Watch Chris Pratt Get Manhandled In His First SNL Promo ]
Actually, the real rip-off is what the Guardians of the Galaxy star did when he was in high school!
Ch-ch-check out the video (above) to hear the entire sordid tale of sketch stealing on The Tonight Show Starring Jimmy Fallon!