Pitching Mammoth must have been a breeze: ‘A 1970s PE teacher is transported to 2024 - hilarity ensues.’ 

You would think that is a pretty solid premise for a comedy commissioner to come across. At worst, it’s raising an agreeable smirk, and even the more sceptical will at least be relieved it’s not another: ‘It’s the story of a millennial, in London, being a bit obnoxious, in London, and they also have mental health problems, in London.’

But as witty and original as the premise for Mammoth is, there’s still a version of this show that could have ended up being more of an elongated sketch rather than a comedy worth its runtime - see Netflix's recent Space Force and Blockbuster flops (and I’d be willing to bet Jerry Seinfeld’s new movie about Pop Tarts, too). 

Thankfully, Mike Bubbins and co-writer Paul Doolan saw this potential hazard miles off and got all the more obvious (if admittedly, hilarious) ‘modern-world clashes’ out of the way in the first five minutes. 

In a well-judged opening montage, we see Tony Mammoth bemused by modern technology, amused by papooses and downright disgusted by the sudden requirement to pick up dog poo - all this, living up to the promise of the concept but crucially, allowing the show to move beyond the expected fish-out-of-water stuff, and get on with the nuts and bolts of establishing some proper foundations for a sitcom with legs. 

I’d seen some publicity that described this show as Life On Mars in reverse - but it’s not, and is all the better for it. The initial high of seeing Gene Hunt wake up in the future and punch his way through a load of health and safety procedures would get old very quickly and it’s clear that the writing duo knew to avoid this ‘old-man-shouts-at-a-cloud’ route for Mammoth. 

By having the character actually want to fit in and adapt, rather than aggressively reject modern life, the show gains a lot more comic mileage. For all his smoking indoors and attempts to seduce his pupils’ mothers, there’s a palpable kindness to Mammoth that draws you in, even when he’s ‘clipping’ kids with his beloved Ford Capri.

Sian Gibson, as ever, is great casting. Starring as a concerned parent of one of Mammoth’s students, she proves once again that she’s the safest pair of hands in British comedy, reliably elevating the odd weak gag with just as much commitment to chasing the laugh as she does with the stronger material. 

Joseph Marcell, probably most famous for being Will Smith’s butler Geoffrey in The Fresh Prince of Bel-Air, is also a fine addition as Roger, the voice of reason, a man behaving the age Mammoth actually should be, but isn’t. And yet - as is revealed in a mid-credits sequence worth sticking around for - he is perhaps more willing to subscribe to Mammoth’s way of life than he lets on.

One weakness comes from Lucy, Mammoth’s head of department, who seems to exist solely as a kind of needless joke-explainer. You’ll find yourself barely midway through a chuckle at one of Mammoth’s contemporary faux pas, before she pops up to point out ‘You can’t do that any more Mammoth!’ - unnecessarily polishing what was already crystal clear. 

This feels like an early script teething problem, common to debut episodes that feel the need to do more spelling-out as part of the initial setup, and it is certainly not the fault of Mali Ann Rees, who deftly plays the character with just the right amount of eyerolling and badgering the script requires. 

But it’s Bubbins who carries this show with a performance that is genuinely a joy to watch. I would go as far to say that if this manages to find an audience, Bubbins may find he has created one of the great all-time sitcom characters. 

As Mammoth, he truly is magnetic - nobly resisting the urge to deliver an over the top, bombastic performance, instead leaning into the characterisation with more subtlety. Most of his biggest laughs are gained from lines he delivers almost under-the-radar, throwaway gems like ‘Mr Freeman has had a mental breakdown. And I haven’t.’ - and it’s these smaller moments that win over the audience early, earning him the kudos to get away with broader gags later, like weightlifting in the middle of parents’ evening.

Mammoth, both character and sitcom, undoubtedly exudes an infectious charm, and hopefully this will spread wide enough to win the show the sizeable audience it deserves.

• Mammoth is on BBC Two and iPlayer at 10pm tonight