Although he only came to public attention last year, Sir Bernard Chumley, raconteur and thespian, is now clearly under the impression that he owns Edinburgh. "Sir Bernard Chumley's Edinburgh," a meaty subsection of his current Gangshow, charts his invaluable contribution to the fringe down the years ("In 1974 I did a poo, in 1975 I did a wee"). So confidently does young Matt Lucas now inhabit his creation, that Chumley stands to become the institution he imagines himself to be. Lucas's performance is a joy to watch, switching from cherubic avuncularity to deranged alter ego with all the violence of radio interference. His blond wig, mischievous eyes, love of crude innuendo and physical catchphrases, make him resemble that other self-knighted egomaniac, Sir Les Patterson, albeit at the opposite end of the sexual spectrum.

As with Patterson though, there is a lurking sense that the character is both too big for hisgags and yet has little imagined life off-stage from which to draw subtler material. These limitations are skated round with the help of David Walliams - whose misogynist stage manager and pig- ignorant royal watcher almost deserve their own shows - but sooner or later, he will have to stop resting on past laurels.

n Assembly Rooms. To 31 Aug