In his novels Fyodor Dostoyevsky was attracted by the grotesque – in Crime and Punishment and The Brothers Karamazov, for instance - and this element is the glue that binds together the substance of Tom Basden's theatrical version of The Crocodile novella. Struggling actor Ivan is incautiously swallowed up by a zoo croc; breathing still, he remains immured in the beast's innards and badgers his friends and his paying public with his pleas and demands while they work to release him from his fetid bondage. The actual crocodile phenomenon put me in mind of Franz Kafka's Metamorphosis in which a man wakes up one day to discover he's been transformed into a giant beetle. This too involved a tragic accident that's twisted by fate and blown up by greed into public spectacle.

The great strength of the play's material is the manner in which it coats thoughtful, today-relevant insights in a layer of farcical comedy. And it is genuinely funny: Thursday's audience laughed a lot, and not just at the verbal squibs that pepper the script. Ivan's pal Anya to him as he groans in the maw of the crocodile:

"Are there enzymes trying to break you down?"

So the zany fun is underpinned by serious themes a-plenty: political allegory lurks in the way that Ivan's friends and other opportunists quickly move in on his plight, tantalised by the sound of a rouble-chewing cash register ringing just before their eyes. In a telling comic-sinister scene, a jobsworth memo-cruncher demonstrates the imbalance of power between them when he seats Ivan's grieving friend Zack on a miniature folding chair. As he takes down the story in triplicate, his inhumanity is complete when he announces nothing can be done since: "the crocodile is a business asset", and then: "he [Ivan] is technically a squatter!".

The script also finds time in the 90 mins. running time to scrutinize the nature of success and failure, taking side-swipes at celebrity culture and how its notions of morality or discernible talent are neutered in the rush to voyeurism. The play, in its focus on Ivan's fight to survive, is also an affirmation of man's desire to struggle on in the face of humiliation and failure; in the latter respect, it also puts in a paradoxical plea for the value of artistic performance in the face of public indifference.

Director Alex Rugman and his colleagues have placed their own black box within the black box theatre, and topped it with their crocodile, an emerald-green draped and lit chair, with convenient hole in the cloth; just a nice size for a victim's head. Was I expecting too much by being a mite disappointed by this croc? I think I had hoped for at least a pair of slavering jaws, if not precisely the scaly skin that launched a thousand handbags. But I did appreciate the queasy mix of garish green and shades of red in the lighting from Jonathan Tanner, and Rugman's patent desire to push the action on while allowing the deceptively dense material to be absorbed by the audience was finely judged.

Dominic Weatherby's Ivan bursts with egoistical energy: now frantic, now magisterial, now pitiful. His bombast is bottomless: "I feel I'm full to the brim of beans!". As the lights go down at the start, first we have a burst of café piano music (by Sarah Spencer; alternately jaunty, then slightly sinister), then Weatherby gets us off strongly as he bewails in a booming voice the dwindling of his artistic ambitions into wormwood and gall: "I was het up. I'm het down now". He then moves inexorably on to rhetoric about his 'duty to the people'. His voice is at once a great strength and a slight weakness, since great clarity of diction is hampered by a certain uniformity of volume and tone that by the end I found a little hard on the ear. In all other respects he was first-class.

Luke Wintour plays with tactful contrast Ivan's faithful friend Zack, struggling to keep the firework grounded, while Kate Weir, a terrific Volpone in November, was a volatile Anya, a pastel confection in a fuchsia semi-tutu, a fairy on top of the Christmas tree. Her reaction to the croc event progressed from piercing screams to pity, and then on to the seeking of selfie opportunities, comfort eating and ultimate opportunism in love. Her acting in the scene where Zach proposes marriage to her was a highlight in a quality performance.

The three multi-role actors backed up their colleagues to the hilt: Julia Pilkington shone as the greedily entrepreneurial zookeeper Popov and later popped up as a startling Tsar in Fu-Manchu moustache and Ivan the Terrible headgear (costumes by Chloe Dootson-Graube; nice!). Jon Berry was an obdurate bureaucrat and obstructive waiter (though his Croque Monsieur/Madame puns were sadly lost on this audience), and El Blackwood was notable as an oily British capitalist.

It's a mystery to me why this multi-faceted drama, progeny of a great novelist and given a thoughtful, contemporary updating by adaptor and translator, is not better known and seen more often. But Nitrous Cow spotted it, have grabbed and run with it, and have exploded a little green bomb on snowy Jowett Walk. Two more days left – go snap up this crocodile!