Koma is a death/black metal and grindcore band from São Paulo, Brazil, operating under an explicitly antifascist, anarchist, and communist ethos. The band released their debut EP "Sinfonia da Desgraça," which blends grindcore, deathgrind, black metal, and sludge metal influences. They are active on Bandcamp under the handle koma5 and present their sound as a direct fusion of extreme music with radical political conviction.

Koriza is a thrash/death metal band from Ilhéus, Bahia, Brazil, with a listing on the Encyclopaedia Metallum that includes the demo "Defluxo" among their early releases. The band operates out of a city better known as a literary landmark — the birthplace of writer Jorge Amado — making them a notable presence in Bahia's underground extreme metal scene. They have maintained an active Spotify presence alongside their long-running career.

Korsakov is a crossover/thrash metal band from Alumínio, São Paulo, Brazil, formed in 2011 and active in the Brazilian underground scene. Drawing on social and political themes — alongside the more irreverent staples of corruption, violence, and rock 'n' roll — the band has released records including Radiation Exposure and Unique Remains. Their sound sits firmly in the beer-soaked, pit-ready tradition of Brazilian crossover.

Korvak is a thrash metal band from Campina Grande, Paraíba, Brazil, formed in 2019 and signed to NoSlip Records. Influenced by old-school death and thrash of the 1980s and early 1990s, the band draws lyrical themes from occultism and social criticism. Their 2023 full-length Chapter II — World's Duality stands as their most developed release, recorded across multiple studios and featuring twelve tracks of aggressive, riff-driven thrash.

Kosmus is a progressive metal band from Rio de Janeiro, Brazil, founded by guitarists Pedro Acker and Sebastian Viret. The band released a self-titled debut album in July 2016, followed by Eudaimonia in 2018, blending heavy riffing with progressive rock textures, jazz-influenced keyboards, and saxophone. Their lineup expanded to include bass, keys, and drums to realise an ambitious fusion of metal and Brazilian progressive music.

Kraftvøid is a São Paulo-based instrumental stoner/doom metal project founded by Gustavo Lima in March 2020. The project pursues a raw, organic approach to heavy music and released its self-titled debut album in January 2022, featuring tracks such as "I Am The Emptiness" and "Fire of a Thousand Suns." Operating without a Spotify presence, the project distributes its music independently through Bandcamp.

Kriegskanone is a death metal band from Manizales, Caldas, Colombia, formed in 2017 and focused on war-themed material. The band released the EP "Tiempos de gloria" in 2017, with members who also play in local acts including Mauser 98 and Militant.

Krifkill is a thrash metal band from Sobral, Ceará, Brazil, formed in 2015. The band's lineup includes Keven on guitar and vocals, Byron on guitar, Madeira on bass, and Fernando on drums. They released the five-track EP State of Despair in June 2016, establishing themselves within the Brazilian underground thrash scene.

Krig is a progressive death metal band from Belo Horizonte, Minas Gerais, Brazil, formed in 2007 and active across multiple stints since then. The band has released albums including Christ Is Public Enemy #1 and the compilations 7 Years of Brutality and the subsequent 17 Years of Brutality series (Volumes I–III), with the latter two volumes arriving in late 2024. Their music addresses spiritual, political, and societal themes within a technically demanding progressive death framework.