Cosmonaut Fuzz is a one-man psychedelic doom metal project from Fortaleza, Ceará, Brazil, created in 2017 by guitarist and vocalist Adriano Alves, also known from the bands Netuno Doom and Sludgeness. The project is entirely instrumental, blending stoner, doom, and space rock into cosmic soundscapes recorded and produced by Alves in his home studio. The self-titled 2017 debut features five tracks including "Rings of Saturn" and "Black Holes Collide," the latter of which appeared on the Escape to Weird Mountain Vol. 3 compilation via Forbidden Place Records.

Cosmophage is a death metal band from Brasília, Brazil, formed around 2022 (with roots in a prior project called Utterance active since 2018). Drawing on the mid-1990s European death metal tradition — particularly the Dutch school — the band plays riff-driven, gutted death metal with occult and cosmic horror lyrical themes. Their debut mini-album "Sidereal Malignancy" was released in October 2024 via Me Saco un Ojo (tape) and Blood Harvest (CD).

Costra is a death/thrash metal band from Osorno led by vocalist/guitarist Alessandro Innocenti, whose debut album "Releasing the Hate" (2014) delivered eight tracks of raw, direct metal sung in both Spanish and English. The band had performed live before the album's release, and their material blends thrash aggression with hard rock directness in the tradition of southern Chilean heavy music.

CounterParts is a melodic heavy metal band from Campinas, São Paulo, Brazil, operating as an independent act. The band explores themes of literature, struggle, religion, and Nordic mythology within a melodic metal framework. Their discography includes the album "A Dreamer Betrayed," recorded and mixed at Basement Studios and mastered in São Paulo.

Cova was a death/thrash metal band from São Bernardo do Campo, São Paulo, Brazil, active in the mid-2000s underground scene before splitting up. The band played aggressive extreme metal with themes centered on death, terror, and Satanism, in the tradition of the Brazilian extreme metal underground. They released demo material independently before disbanding.

Cova Rasa is a heavy metal band from São Paulo, Brazil, founded by guitarist Jayme Danko and keyboardist Collins Freitas. The band plays traditional heavy metal with horror-themed lyrics drawing on urban legends, serial killers, and supernatural narratives, and has released albums including "Deadline" (2018), "Cruzando Infernos" (2020), and "Another Time" (2025). They have served as opening act for international touring acts including Rhapsody of Fire and HammerFall in Brazil.

Cova Raza is a thrash metal and crossover band from the Pouso Alegre and Borda da Mata area of Minas Gerais, Brazil, formed in 2015. The band operates independently and plays aggressive thrash with crossover hardcore influences, with lyrical themes covering death, violence, and social critique. They contributed a track to the Brazilian metal compilation "Sons de Guerra" on Roadie Metal (Vol. 13, 2019).

Coveiros is a metal band from Porto Velho, Rondônia, Brazil, one of the more isolated corners of the Brazilian extreme metal underground. Beginning with a hardcore and early death metal approach, the band shifted toward thrash and death metal over time, releasing a self-titled album in 2007 featuring fourteen tracks. They remain active as an independent act in the Porto Velho metal scene.

Coveirö was a raw black metal project from Curitiba, Paraná, Brazil, active briefly in 2024 before splitting up. The project was driven primarily by the musician Calazar, who handled bass, vocals, guitars, and synths, with Naberius contributing drums as a session player. Their track "Coveiro Necromante," recorded at Neon Records in March 2024, blends depressive and raw black metal aesthetics within Brazil's underground extreme metal scene.