I have seen the future of comedy and it is We Are Klang. Well, maybe not quite, but their demented, vulgar, messy, knockabout, surreal sketch show certainly tickles the funny bone more frequently than most shows on the Fringe. It takes genuine genius to appear this gormless.

There is no philosophy, no concept, no theme. Greg Davies, Marek Larwood and Steve Hall simply hurl everything into their quest for laughs.

Which means that Davies stuffs his mouth with Jaffa cakes, Larwood wears a ludicrously lumpy blue body stocking and Hall reveals his talking bottom, an act so puerile it transcends offensiveness.

It helps that the trio all look like classic clowns. As is always noted, Davies resembles a fat Rik Mayall. Larwood has Matt Lucas's hairstyle and Marty Feldman's bug-eyes, Hall is all deadpan, repressed rage. Together and separately they produce sublime moments.

Elsewhere Larwood's Tracey Emin impression treads familiar comedy water before hitting gloriously grotesque extremes. Best, however, is Davies's Vic and Bob-ish justice-delivering Legal Eagle, who struts around the venue handing out random prison sentences to audience members while sweating profusely and wearing a bird's beak. The verdict on Klang? Guilty of the grossest form of comic brilliance.

Until 27 August. Information: 0131 556 6550.