Foetus is the primary musical outlet of industrial music pioneer J. G. Thirlwell. Until 1995 the band underwent various name changes, all including the word foetus. Monikers adopted at different times include Foetus Under Glass, You've Got Foetus On Your Breath and Scraping Foetus Off The Wheel. After 1995 the name permanently became Foetus, though the related project The Foetus Symphony Orchestra was founded in 1997 and continues.
Thirlwell acts as the sole instrumentalist, vocalist, songwriter and producer for all Foetus works and as such is the only member of the band. Other artists may occasionally collaborate with Thirlwell on Foetus works but are not considered members of Foetus. Thirlwell is solely responsible for the musical output of the band.
J. G. Thirlwell has many side-projects, in which he frequently goes by the name Clint Ruin. In One such grouping is Wiseblood with former Swans member Roli Mosimann. The material tends toward the realm of the darkest and most sexual Foetus songs, with Mosimann's Swans lineage showing in the slow, crushing pacing of many tracks. Thematically, Wiseblood's lyrics center around the misanthropic exertion of power, typically via murder, sex or assault. Wiseblood existed on-and-off from the mid 1980s through early 1990s.
The artwork of Foetus releases shows a deliberate progression of colour: the earliest releases are black and white, with the addition of red on the Deaf album, and further addition of yellow on Nail. Full-color art was introduced on Gash. Beginning with Flow, the artwork of primary albums reverted to black/white/red, though other releases continue in full colour.