Perturbed by negative reviews and delighted to have outed another scribbler in the darkness, Sam Campbell seems to have a special talent for hijacking his own act. Why else would this shambolic young Aussie spill Sprite over a member of the front row and throw out some lewd material when he knows full well there are a couple of minors attending his 12+ hour (the classification of live comedy shows where literally anything can happen remains one of the more curious Fringe innovations in recent times)?

But at the root of it all, there's nothing more sinister about Campbell than a predilection for the highly mischievous. With nervous laughter, he kicks proceedings off with a song about mums and dads before deliberating over the pros and cons of necks. There's some quasi-surreal chatter about ants and axolotls, while his photos of famous Aussies who are totally unknown on these shores adds to the sense of delirium.

Rumour has it that James Acaster is a big fan of Campbell and there's something in the delivery, manner and dress sense (roll neck and sensible trousers) that hints of a mutual admiration. Tottering permanently on the verge of alienating his crowd, Campbell pulls it all back with an off-piste approach and genuinely intriguing stage persona.

Assembly Roxy, until 28 Aug, 8.15pm, £9–£12.