Ancienterror is a death/thrash metal band from Santiago, Chile, formed in 2002 from the ashes of Missing Sequence, and has remained active in the city's underground scene ever since. The band released the EP "Arguments for Aggression" in 2007 and has built its lyrical identity around anti-religious, anti-globalization, and anti-capitalist themes.

Ancillae is a death/thrash metal band from Carazinho, Rio Grande do Sul, Brazil, formed in 2024. A recent entry into the Brazilian extreme metal underground, they combine the brutality of death metal with the aggression and riff-driven attack of thrash.

Anger Cult was a death/thrash metal band from Jaraguá do Sul, Santa Catarina, Brazil, active from 2017 until splitting up. They released an EP titled "Bringing Order Through Chaos" in 2017, delivering aggressive, riff-driven extreme metal in the tradition of Brazil's underground death-thrash scene.

Anhaguama is a death/black metal band from Arujá, São Paulo, Brazil, formed in 2019 and operating in the underground extreme metal scene of greater São Paulo. Their music draws from the aggressive intersection of death and black metal, a tradition with deep roots in Brazil's extreme metal history.

A death/thrash metal band from Rio de Janeiro with roots stretching back to the mid-1980s underground scene, founded by guitarist Alberto "Urubu" Lemos. The band built a reputation through raw demo recordings and aggressive live performances before releasing their 1997 album "Fate" on Kaos Records, which drew attention from the worldwide underground circuit. Their sound draws on the hard-edged Brazilian thrash tradition, with lyrical themes centered on war, societal collapse, and political decay.

Antagonyze is a death metal band from the Bio Bio region of Chile, founded by guitarists Ignacio Riveros and Francisco Álvarez and bassist Mateo Gutiérrez. The band released the demo cassette Echoes from Soul in 2020 and later re-recorded and expanded that material into their debut full-length Interpretations of the Unknown Wilderness, released in April 2024 on Chaos Records. The album was recorded at Estudio Chains in Los Ángeles, Chile, and drew praise for its old-school 1990s death metal approach with thrashing, prog-inflected intensity.

Antropofectus is a death/black metal project from Magé, in the Baixada Fluminense region of Rio de Janeiro state, Brazil, formed in 2021 and currently on hold. Blending the aggressive tremolo-heavy assault of black metal with the low-end brutality of death metal, the project is part of Rio de Janeiro's active underground extreme metal network. They released music independently through Bandcamp.

Apofenia is an old-school death/thrash metal band from the city of San Luis, Argentina, formed in late 2015 and playing their first show in January 2016. The band released their debut demo "Peste" in July 2016, a five-track assault featuring tracks like "Descuartizado" and "Muerte" rooted in brutal, no-frills extreme metal. Driven largely by siblings Anabelle Escudero on drums and Gisselle Escudero on guitar and vocals, Apofenia became one of the more notable all-female extreme metal acts in Argentina's interior provinces.

Apokalyptic Raids is a black/death/thrash metal band from Rio de Janeiro, originally formed in 1998 as Apocalyptic Raids — a name drawn directly from a Hellhammer EP — before adopting the current spelling in 2001. Driven by guitarist and vocalist Leon "Necromaniac" Manssur, they have released a string of albums and splits since their debut "Only Death Is Real" (2001), channeling the proto-black metal ferocity of Hellhammer, Bathory, and Vulcano while collaborating with acts like Whipstriker and Atomic Roar.