Movarbru are a long-running Satanic black metal band from Sapiranga, Rio Grande do Sul, whose sound draws from the raw South American underground tradition. Their 2020 EP 'Sob o Domínio do Antigo Culto,' recorded at From Hellcords Studios in Porto Alegre, was released as a 300-copy limited edition through Cianeto Discos and features the band's core themes of occultism and anti-Christian fury.

Mr. Ego are a power and progressive metal band founded by brothers Júlio (vocals) and Paulo André (bass), drawing from Helloween, Angra, Dream Theater, and Symphony X. Their 2009 album 'Mythology' is a concept record built entirely around ancient Greek mythology, and their subsequent release 'Se7en' features Symphony X bassist Mike LePond as a guest on one of its tracks.

A shred-focused heavy metal outfit from the port city of Santos, Mr. Green traded in technically demanding guitar work within a classic heavy metal framework. The band operated as an independent act and left behind an instrumental-leaning legacy before splitting up.

Mud Crows is a post-metal band from Adrogué, Buenos Aires, Argentina, comprising Mariano Nunes (vocals), Julian Nunes (guitar), Rodrigo Mendoza (bass), and Gustavo Liberzone (drums). They released the album Nacimiento de un Ser in 2018, recorded at Rockville Studios in Banfield, and followed it with the Rulieh EP in 2020.

Mudness is a stoner-doom trio featuring Renan Casarin on guitar and vocals, Fernando Dal Bó on bass, and Pedro Silvano on drums. Their 2023 self-titled debut, recorded at Célula Showcase studios in Florianópolis and produced by Leandro Lazzarotto, delivers seven tracks of heavy, riff-driven doom that circles themes of human fragility and social decay.

Mudrost is a black metal solo project by Hellsgaard, born in Curitiba in 2022 and prolific from the start. The project released "Melancholy State of Soul" in August 2022 and followed it with "Sanctum Regnvm" in January 2023, establishing a cold, uncompromising sound rooted in orthodox black metal traditions.

Muerte Akción is a crossover thrash band from Santiago, Chile, formed in 2012 by guitarist/vocalist Rodrigo de las Riberas, bassist Sandino Muñoz, and drummer Rodrigo Herrera. Their politically charged lyrics tackle themes of colonialism, inequality, and Chilean social tensions, with releases spanning the 2012 EP through the albums Fuego (2014), II (2015), and Dominio (2022).

Mufa is a São Paulo extreme metal act that draws equally from death metal brutality and hardcore aggression, keeping a stable lineup since 2011 while channeling outrage at social rot into relentlessly violent music. Their 2015 debut full-length "Brutality Show", recorded at Magma Studio, showcases their genre-defying blend with tracks like "NarcoViolence" and "Disposable Human Race".

A stalwart of the Goiânia metal scene, Mugo mixes death metal heaviness with thrash energy and pronounced groove, drawing comparisons to Obituary and At the Gates. Their discography spans multiple full-lengths including "Go to the Next Floor" (2009), "Race of Disorder" (2017), and "Tempest" (2019), each refining their brand of extreme metal with elaborate harmonies.