In 1989, Mullen, Hobbs, and Smith formed Suffocation with bassist Josh Barohn and guitarist
Doug Cerrito. Suffocation released the six-song EP
Human Waste in 1991. The EP was one of the first records released by
Relapse Records. The band released their second full album
Breeding the Spawn in 1993. The album was criticized for "its short length", "its perceived repetition of the predecessor's overall formula" and a "muddy final mix". In 1995, they released
Pierced from Within, "one of Suffocation's strongest albums" according to
Rolling Stone. The band recorded an EP,
Despise the Sun, in 1998 and released it through their band management company Vulture, though it was not in wide circulation.
Despise the Sun featured a different drummer, Dave Culross, who would later again replace Smith in 2012. , Derek Boyer, and Mullen in 2010 Suffocation subsequently broke up and did not reunite until 2002; that year, Relapse Records re-released
Despise the Sun. The newly re-established band included Mullen, Hobbs, Smith and Barohn, with returning member Guy Marchais, previously with the bands Pyrexia and Internal Bleeding.
Pitchfork said of Mullen's vocals, while "he spews tales of madness, megalomania, and paranoia", his "growls are surprisingly understandable". After the release of the 2013 album
Pinnacle of Bedlam, Mullen announced that he would retire from full-time touring from the band.
Pinnacle of Bedlam saw the return of drummer Culross to the band since his previous appearance on
Despise the Sun. Mullen and Hobbs became the only remaining original members of the band after the departure of Smith in 2012, who had filled in for him on several occasions. Mullen later reprised his role for the band's Japanese tour in 2019 before again relinquishing the position to Myers. == Artistry ==