Judging from Ween's stage setup Sunday night, you'd expect them to be a skinhead hardcore band; distributed across the stage of the Somerville Theater were a bass drum with a flipped bird painted on the front, a party bottle of Jack Daniels and a riot gear-looking bullhorn. The fans that packed Davis Square's venerable fountain of obscurity know the truth about alt-rock's satirical brats, though: Ween is just kidding.

Ween is part rock band, part comic circus and part junior-high bus ride. Frontmen Mickey Melchiondo and Aaron Freeman hooked up 15 years ago at age 14, adopted the monikers Dean and Gene Ween, and haven't stopped playing (or grown up) since. Ween had their first major label with 1992's Pure Guava and have since logged a string of studio and live albums. Their 1997 release The Mollusk, with its blatantly thecal cover, will undoubtably go down in the annals of rock as the album that gave NOFX's Heavy Petting Zoo the best competition for most obscene cover art. For the most part, though, it has been the live shows with a full band that have won Ween so much love from its fans. Sure, they could listen to "Waving My Dick in the Wind" at home, but could it really compare with seeing Gene Ween striking David Lee Roth poses while singing it live?

Watching guitarist Dean Ween rattle off a blatant parody of a Soundgarden solo, tongue out with Michael Jordan-like abandon, any doubts about what was to be taken seriously and what was a joke were gone. It was all a joke and a good one at that. Dean and Jordan seem to have the same thought in mind while doing their thing: "this is way too much fun, I can't believe they're actually paying me to do it!" Singer Gene seemed to be having an equally good time. When the rest of the band stepped off stage "to take a leak," leaving him to play a lighter-waving ballad, he barely managed to keep a straight face through the second verse. Though the band's musical mix of grungy alt-rock and bouncy hoe-down country would have made for a decent concert by itself, it was their presence and stage antics that made it a truly great, entertaining show. Though the brothers Ween may be known for their adolescent humor and cheap laughs vulgarity, their on-stage satire was surprisingly incisive. At one point the band even asked for the house lights to be brought up and then proceeded to shoot pictures of the audience, bringing into legitimate question who was entertaining whom.

Sunday's crowd was made up mostly of bona fide, Ween T-shirt-wearing fans. Most clocked in at well over half baked and still smoking, not surprising for the followers of a band known for its recreational use of Scotchguard. There were also a surprising number of 30- and 40-somethings, most of who were singing along with the college-age masses. The enthusiastic audience filled the normally calm theater to cramped standing room, inspiring the band to attempt their P-Funk-parodic magnum opus. "Okay, this hasn't worked for the last six nights," Gene told the crowd, "But if we all concentrate really hard I bet we can get the Poop Ship to descend on Butt-F**k, Mass., or wherever we are." The next 15 minutes could only be described as a paean to the mothership of all things flatulent. It began as a trudging grind-core chant to the ship itself, progressed through a rendition of every fake farting noise that can be coaxed from the human body and came to a head with an extended lounge jazz breakdown. The Poop Ship never did come through for Ween, but that didn't stop them from delivering a great show for their fans and entertaining the uninitiated. So what if it's all a joke?