Easily identified by their distinctively grotesque costumes, Gwar's core thematic and visual concept revolves around an elaborate science fiction-themed mythology which portrays the band members as barbaric interplanetary warriors, a narrative which serves as the basis for all of the band's albums, videos, live shows and other media. Rife with over-the-top violent, sexual, and scatological humor typically incorporating social and political satire, Gwar have attracted both acclaim and controversy for their music and stage shows, the latter of which notoriously showcase enactments of graphic violence that result in the audience being sprayed with copious amounts of fake blood, urine, and semen. Such stagecraft regularly leads Gwar to be labeled a "shock rock" band by the media.
Since their formation, Gwar have released thirteen studio albums, two live albums, and numerous singles among other recordings, and have sold over 820,000 records in the United States. Fueled largely by the controversies surrounding their concerts, Gwar experienced brief mainstream notoriety during the first half of the 1990s, receiving regular airplay on MTV as well as frequent in-character guest appearances on daytime talk shows, satirizing the topics of censorship and media violence. Though the band's mainstream popularity declined by the end of the 1990s, Gwar has retained a dedicated cult following. The band's extensive videography consists of both live recordings and long-form feature films, most notably 1992's Phallus in Wonderland, which earned a Grammy Award nomination for Best Long Form Music Video. Outside of music and video, Gwar has expanded their franchise into comic books, trading cards, a board game, signature beers, barbecue sauces, and e-liquids.
The band's characteristic costumes are generally made of foam latex, polystyrene foam, and hardened rubber. The costumes cover very little of the band members' bodies; the bare parts are accentuated with makeup. They further their production in concert by spraying their audiences with fluids. Most of the fluids are made of water and powdered food coloring which, for the most part, flakes off or washes out easily. The thicker fluids are made from a clear seaweed extract called carrageenan, which is also used in ice cream and milkshakes. Gwar does not use syrups or stage blood because they dry solid and can damage the band's costumes.