Craig Ferguson’s final night as host of Late Late Show airs tonight. It’s maybe his toughest gig ever, coming one night after Stephen Colbert said so-long to The Colbert Report so he could move to CBS and take over for David Letterman.

SPOILER ALERTS HERE. The audience is warmed up with a look back at all the celebrities who’ve marveled at how unabashedly silly is his show, including Archbishop Desmond Tutu telling him, “I think you’re crazy”; Denis Leary, who “thought the show was going to kind of make sense”; and Julia Louis-Dreyfus, who famously told Ferguson,  “You’re an idiot.”

Craig Ferguson final showA rousing musical opening, including a Bang Your Drum music video makes you sad that neither Worldwide Pants nor CBS ever thought it worth spending the money on a band for the show. A celebrity-studded video features Dead Man Fall — a group from Craig’s hometown in Scotland — performing a version of their song Bang Your Drum. It transitions to the Late Late Show stage, where Ferguson is singing the tune, and band Bone Patrol is performing the song live.

The live performance on stage features Steve Jones performing with the band Bone Patrol, Craig singing, and a gaggle of celebrities joining in, including Kevin Bacon, Quentin Tarantino, Archbishop Desmond Tutu, Pierce Brosnan, Steve Carell, Don Cheadle, Jeff Daniels, Ted Danson, Kat Dennings, Julia Louis-Dreyfus, Tony Hale, Jon Hamm, Samuel L. Jackson, Jimmy Kimmel, Lisa Kudrow, Jane Lynch, Matthew McConaughey, Tim Meadows, Metallica, William Shatner, Michael Sheen and Henry Winkler.

A video zips through time, showing Ferguson opening the show every episode from his very first until tonight. “Ugh! Never do that!” Ferguson groans.

“You came to a show that was, let’s be honest, a bit of a fixer upper and stayed that way,” Ferguson said by way of thanking viewers. “What I hope we’ve done is maybe try – ‘art’ is a very grand word, but what I think I was trying to do here, and think we managed to do here, is make something that wasn’t here before. In that sense, maybe it is a piece of art. And you will be able to find it forever on YouTube. What I meant to say was CBS’s web site,” he joked.

“Really, this show belongs to you. And I hope you keep it – because I’m done with it.”

Ferguson said “I think that what’s more overwhelming than anything else in this experience doing the show is the connection with a country which I became part of, which is astonishing to me. And now, even in the course of this show I became an American officially and, particularly for my friends at the IRS, I am now a full-fledged American.

He implored viewers to “come to whatever I do next,” saying, “I’d be grateful, because my kids are still young.”

In that vein, he and sidekick Geoff Peterson, a robot, decide to introduce a new character on the show’s final night: Pipe-y The Scottish Pipe. “You’ve been sticking me in your mouth for years – you rat bastard,” Pipe-y scolds Ferguson. “Ewww!” moans the audience. “Did they just ‘Ewww’ me in my last show?!” Ferguson wails. And during a regular segment in which he reads viewer emails, he comes across one in which a guy wonders if Ferguson would do him the “honor” of reading his email on the final show and, if so, could he see if there is anyone at the door. This triggers another Late Late Show regular gag, in which the show’s pantomime horse races around the set.  “I feel for people tuning in for the first time,” Ferguson giggles.

Craig Ferguson final show Jay LenoThey talk about how dirty the set is these days since no one has cleaned it, what with the show ending. More dirt means more celebrity flies — another show staple. Jay Leno fly, Jimmy Fallon fly, Bill Cosby fly — all are swatted by Ferguson while Geoff’s alter ego, comic Josh Robert Thompson, provides fly voiceovers. A “try this drink!” Bill Cosby fly line will not make the broadcast.

Geoff notices Ferguson’s wearing the same socks as he had the previous night. This is because they tape the Thursday and Friday night shows on Thursdays. “Here the thing: so does everybody else. Like when you see Game Of Thrones. That isn’t happening right then – that happened ages ago,” explained Ferguson, unconcerned.

Ferguson’s only guest tonight is Jay Leno. “Two guys out of a job,” notes Jay, adding, “they may take our talk shows – they will never taken our freedom!” Craig wonders if Leno ever said ‘fuck’ on Tonight Show. They comment on each others’ hair – Jay’s is longer, and whiter, and Craig’s is cut severely short on the sides  — more “Mohawk,” explains Craig, who suggests Jay follow suit. “I don’t play that many Indian casinos,” Jay cracks. The audience loves it.

Jay says he likes doing standup, as opposed to a talk show, because he doesn’t get any notes from network execs, informing him the show isn’t doing well with “immature boys between 12 and 13” and wondering if he has any “silly string gags.” The two veterans agree they both hate publicists.

Jay says he knew it was time to leave Tonight Show when fewer and fewer people understood his references —  like the time a young female reporter came to interview him for her school newspaper, and asked if she could have her picture taken with him and he directed the photographer to get the shot with him and Lois Lane, and the reporter and photographer informed him that was not her name. “That doesn’t make you old —  that makes them stupid!” Craig stoutly insisted.

They’re out of time. “I’m so glad you agreed to be my last guest,” Craig says. Jay returns the compliment, saying he’s always admired Ferguson, who has been a good friend, adding, “You didn’t join the Late-Night Talk Show Snippy Club.”  Leno’s apparently still mulling the drubbing he received over the years at the hands of CBS’s other late-night guy David Letterman, and ABC’s Jimmy Kimmel. The two men hug.

Wrapping the show, Craig and Geoff note one thing people never learned over the course of the show was who is inside the pantomime horse. It’s a segue to a taped bit in which Bob Newhart is revealed to be one half of the horse —  only Craig wakes up and realizes it’s all been a bad dream, which he begins to tell to his bed-mate,  mirroring Newhart’s famous sitcom finale scene. You’ll have to tune in tonight to see how it plays out.

Earlier in the week, Ferguson said that 2009 interview with Desmond Tutu —  for which Ferguson was awarded a Peabody — had led to this moment. The Peabody selection committee cited the critically acclaimed interview as proof that “one of the silliest hours on television (what with the trademark hand puppets and skeleton robots) could also be one of the smartest.”

“This is a man who talked to some crazy motherf****rs,” Ferguson explained during a celebration of his show at the Paley Center for Media in Beverly Hills. “He said to me, ‘You’re crazy – I don’t mean to be rude.’ I said, ‘I thank you, Father Tutu.’ He said, ‘No,  you are crazy, but the type of crazy we need.’ And, this is not your agent, you know, he’s not like, ‘Keep doing the crazy thing!’ It’s Desmond Tutu saying ‘Be as authentically crazy as you are.’ It was kind of like God saying ‘Just be as crazy as you like.’ I felt weirdly released by that.”

“Then, ultimately, that leads to me not doing the show,” Ferguson said.