With one exception I can't think of many fakes that even attempt to taste like the right thing. Usually it's just a volume/color match with another beer, and since the fakers rarely use beer guns or any kind of sanitation they're usually oxidized
and infected.
That exception being a bottle of Crianza Helena that
Dunt opened at a Cantillon share a few years ago. Once he tasted it he was pretty certain someone just slapped a Crianza label (not hard to come by, btw) onto a 2008 Classic Gueuze. The big difference between then and now is that the Cantillon bottling dates are incredibly well documented on some website whose name I can't bother to remember.