Sub Pop released Mudhoney's debut EP Superfuzz Bigmuff.
The EP was released in October 1988 and helped establish Mudhoney as one of the central bands in Seattle's developing grunge scene. Its title combines the names of two guitar effects: the Univox Super-Fuzz pedal and the Electro-Harmonix Big Muff distortion and sustain pedal.
Sub Pop, founded in Seattle by Bruce Pavitt and Jonathan Poneman, became closely associated with the early grunge sound. Its releases and marketing helped draw international attention to the local scene before major labels signed several Seattle bands.
Superfuzz Bigmuff was not Mudhoney's first recording in every sense: the band had already issued the “Touch Me I'm Sick” single in 1988. However, the EP became an important early statement and was later reissued with additional tracks. The label is sometimes confused with SST, an independent label that released influential punk and alternative records but did not issue this EP.