Corujas is a raw black metal band from Catanduva, São Paulo, Brazil, active since 2013. The band's lyrical themes center on nature and birds — "corujas" means owls in Portuguese — placing them within the tradition of Brazilian raw black metal acts that draw on the natural world for imagery. They release music independently through Bandcamp.

Cosecha Lagrimas is a melodic death metal band from Mar del Plata, Argentina, drawing clear influence from the Scandinavian melodic death tradition — their Bandcamp catalog includes the tracks "Corazón Flamígero" and "Animus Meminisse Horret", and in 2016 they released a live EP alongside a recording of Sentenced's "May Today Become the Day". The band celebrated their seventh anniversary with a live performance in Mar del Plata in 2014, marking them as one of the longer-running melodic death acts on Argentina's Atlantic coast.

Cosmic Abyss is a progressive thrash metal and crossover band from Brasília, Distrito Federal, Brazil. They combine the technical aggression of thrash metal with crossover punk energy, and their thematic focus on cosmic and futuristic subjects sets them apart within the Brasília underground scene. The band is independent and active.

Cosmic Rover is a stoner metal trio from São Paulo, Brazil, formed by drummer and vocalist Edson Graseffi (formerly of Panzer), bassist Rodrigo Felix, and guitarist Xande Saraiva of Baranga. The band blends stoner rock, heavy metal, and southern rock influences, recording their albums live in the room to capture an organic 1970s feel. Their second full-length album, Heavy, was released in December 2021 via Abraxas Records.

Cosmic Sepulcher is a death/doom metal solo project from Euclides da Cunha, Bahia, Brazil, formed in 2024 by multi-instrumentalist Athayde Neto, who handles all instruments, vocals, recording, and production. The project draws on cosmic horror and the Cthulhu Mythos for lyrical inspiration, crafting dense, funereal compositions that explore dark fantasy and existential dread. Neto is also active in the bands Wiseblood, Töhil, and Adumbrall.

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.