I'm A Celeb: Will it work with Holly Willoughby instead of Ant?
When I'm A Celebrity returns to ITV for an 18th series tonight, one thing will be very different.
Ant announced in August that he wouldn't return to work until 2019, after admitting drink driving following a car crash in March.
Dec wished Ant a Happy Birthday on Twitter on Sunday morning. Not long ago the two not being together in the jungle would've been unthinkable.
But it's going to happen, so will it work? Radio 1 Newsbeat looks at how other shows have got on without their popular presenters.
Olly Murs fans might not want to carry on reading. Sorry Olly.
Bruce Forsyth and Strictly Come Dancing
It doesn't always go well when you lose a presenter (we'll get to that later) but Strictly made it seamless.
Bruce was 86 and 11 series into Strictly when he decided he'd rather watch the show with his slippers on at home. Claudia Winkleman, former host of spin-off show It Takes Two, was given a promotion.
She'd already taken over presenting the results show from Bruce two years earlier.
"Bruce stepped down so there was no backlash against Claudia," TV critic Emma Bullimore tells Newsbeat.
"Claudia was a friend of the show like Holly is a friend of Ant and Dec, so it feels very organic, very natural and what you might expect to happen."
The ratings have continued to soar and, while it's big rival The X Factor has struggled, Strictly is now the undisputed king of Saturday night.
Dermot O'Leary and The X Factor
Here's how not to do it. Even back in 2015, when it was announced that Dermot would be leaving The X Factor, the show was losing ratings.
He had proved really popular in the role after taking over from Kate Thornton in 2007.
But Simon seemed to decide that bringing in Olly Murs and Caroline Flack would be a good idea to freshen things up. It didn't work out.
The ratings didn't improve and Olly didn't seem to take to presenting. Remember when he told one contestant they were going home when it was actually going to deadlock? It was all very awkward.
"Presenting is a job which looks easy but is actually very difficult," TV critic Emma explains.
"X Factor viewers love Olly but it just didn't work. They tried to mix it up a bit, Simon's always looking for ways to do that since the show has been on the decline.
"He's been desperately trying to save it and that was an idea. At least props to Simon. After one series they said 'no this is ridiculous'. It just didn't go well."
Dermot came back a year later. Many of the viewers still haven't. The 2018 series has seen some of the lowest viewing figures in its history.
Clarkson, Hammond & May and Top Gear
When Jeremy Clarkson's BBC contract wasn't renewed, after an "unprovoked physical attack" on a Top Gear producer, it brought to an end one of its most popular ever presenting line-ups.
Top Gear has had many hosts over the years but the three presenters' chemistry in the Clarkson era saw the show soar to new heights.
Since then Chris Evans came and went very quickly and that led to a decline in viewing figures. The critics weren't kind either.
Under a new trio of Matt LeBlanc, Chris Harris and Rory Reid, the show's reputation improved and the numbers crept back up slightly.
But Matt's now decided he's had enough so Take Me Out host Paddy McGuinness and ex-cricketer Andrew Flintoff will join Chris Harris for series 27.
Who knows how this latest line-up will fare. Will it hit the heights of the Clarkson, Hammond and May era?
The Great British Bake off and Mel & Sue
The Great British Bake Off is the surprise hit of the 2010's - becoming one of the most watched shows on British TV.
Fans loved the chemistry between the judges and hosts. But, when the show switched from the BBC to Channel 4, there was an exodus.
Love Productions, which makes Bakes Off, got a better offer from the commercial channel.
Mel and Sue quickly said they "wouldn't follow the dough" and Mary Berry quit too, leaving only Paul Hollywood remaining.
The ratings are lower but still healthy and new hosts Sandi Toksvig and Noel Fielding appeared to win round many fans.
"It became such a big shift that you either loved the format of the show and you were going to go with it, or you weren't," Emma says.
"Everyone loves how Mel and Sue hosted but Sandi and Noel don't do it that much differently. They like to say they do but really it's a very similar tone.
"I think it has worked. It's not quite as magical as it used to be, but it's still a great show."
Holly Willoughby and I'm A Celebrity
So how will Holly get on keeping Ant's jungle seat warm? Emma thinks viewers will stay with the show.
"What elevates I'm A Celebrity from other reality shows is that Ant and Dec take the mickey out of the contestants, like two little naughty boys giggling at them.
"It's an integral part of the show and people are very nervous about the fact that they won't be there together.
"But it's a needs must situation. What other choice did they have unless they were going to take the show off air?
"Holly has been very careful to say this is only for a year. No one think's she's trying to take's Ant's job. Holly is also very cheeky. We've seen her and Phillip Schofield losing it on This Morning and that's what you want for I'm A Celeb."