At some point or another, everybody has heard 'Carry On Wayward Son.'  It's one of those classic rock songs that you just can't avoid.  Not everybody has heard it being covered by GWAR though. 

A.V. Club

I guess Starbucks is did a whole series of weird covers, but I have to assume that GWAR is the weirdest.  When I go get a Venti Mocha Choka Latte or whatever they sell, the last thing I would expect to hear is Oderus Urungus and crew.