Clint X Eastwood is a raw black metal and grindcore band from Catanduva, São Paulo, Brazil, formed in 2023. The band's lyrical themes revolve around Clint Eastwood films, an unusual conceptual hook within the Brazilian underground extreme metal scene. They released a self-titled demo in May 2023, available on Bandcamp.

Cloud of Shadows is a metalcore band from Quilmes, Buenos Aires, Argentina, whose sound is rooted in the Gothenburg melodic death metal tradition with clear influences from In Flames, Arch Enemy, and Dark Tranquillity. The band released their third album Rodeando el Abismo in 2022 and have maintained nearly continuous activity, with a fourth studio record in progress as of 2026.

Coagular is the solo progressive death metal project of Christian Barzallo, an Ecuadorian musician from Quito previously known as the vocalist of Reject Messiah and a member of Ergosvm and Vril. The project blends death metal, grindcore, and progressive metal into a melodic and introspective sound, with releases including the 2025 EP Edictvm Perpetvvm.

Coagulo was a death metal band from San Juan, Argentina, formed in 2015 and later split up. The five-piece lineup featured Julián Ibars on vocals, Martín Manrique and Julio Rosales on guitars, Elías Vega on bass, and Daniel Fernández on drums.

Cobalto was a thrash metal band from Salvador, Bahia, Brazil. The band's lyrical themes encompassed politics, evil, and darkness, and they released the album "Elemental" on Torto Fono Gramas before eventually splitting up. They are listed on Metal Archives as a defunct act.

Coccyx is a brutal death metal band from Minas Gerais, Brazil, an independent act that has remained active across multiple periods of activity. The band released a self-titled album in 2018 and appeared on the Brazilian metal compilation "Map of Hell" via UGK Discos (2017). They operate within the fertile Minas Gerais extreme metal underground.

Coffin Trip is a blackened death and doom metal band from Pelotas, Rio Grande do Sul, Brazil, formed in 2025. The band released their debut album "Pathless Endeavor" in April 2025, with tracks including "Selenic Sun." Their sound blends blackened death metal with doom and doomgaze textures.

Coffinfeeder is a death metal band from Sabará, Minas Gerais, Brazil. The band has recorded material including the track "Enslaved by Ignorance" and maintains an active presence in the Brazilian underground death metal scene. They operate independently and have a Bandcamp page under the handle coffinfeeder666.

Coherence is a progressive metal band from Campinas, São Paulo state, Brazil, active since 2016. The band has released albums including "Of Alternate Spaces" and an EP, with a 2020 remastered edition of "Of Alternate Spaces" available on their Bandcamp page. Their music blends progressive metal structures with experimental and atmospheric elements.