Molitium is a heavy and progressive metal band from Santa Catarina whose 2018 debut album "Progeny" laid out a sound rooted in melodic guitar work and dynamic song structures. The record featured guest appearances from Marcelo Braga across multiple tracks, giving it a collaborative texture uncommon for a debut release.

Moloch is a black metal band from Recife who have sustained an underground output since 2007, releasing a sprawling catalog of splits, EPs, and albums across more than a decade. They have collaborated with international acts including Hermóðr, Nocturnal Depression, I Shalt Become, and Wedard, situating themselves firmly within the global depressive and raw black metal underground.

Monasterium was a death/doom/gothic metal band from Teresina active in the late 1990s, releasing the full-length "Innocent Rise" on Demise Records in 1999 and a demo titled "Inviolable" in 1998. Their sound blended the heavy melodic sensibility of gothic doom with death metal weight, placing them among the more ambitious extreme acts to emerge from the Piauí underground.

Monje is a stoner/doom metal band from Buenos Aires, active since 2016, featuring guitarist Diego Petullo, vocalist Matias Ibañez, bassist Lucas Scardamaglia, and drummer Diego Hernandez. The band has released three studio albums — Monje (2018), Druga Dimenzija (2020), and Culto al Fin de los Tiempos (2023) — alongside a live album, Igual de Macabro: Live Bunker (2022). Their later work incorporates dissonant harmonies, blast beats, and black and death metal influences alongside the core doom sound.

Mono Histeria is a Curitiba outfit blending progressive, doom, and stoner metal into a dense, riff-driven sound. The band released "Volume 1" in 2022 and has tracks such as "Instinto" and "Primata" available on streaming platforms, pointing toward a sound influenced by the heavier end of the psychedelic and doom rock spectrum.

Formed by guitarist/vocalist Wallas Ribeiro, bassist Murilo da Silva, and drummer Gustavo Silveira, Monolito blends groove-heavy riffing with progressive structures and hard rock roots. Their 2023 album Voice of Rage, produced by Gustavo Vasquez at RockLab studio, showcases a denser and darker direction across eleven tracks while retaining the melodic sensibility that defines the band.

A project embedded in the Brazilian depressive black metal underground, Monophobia released the single "Recomeço Sem Início" on PutreRecords and the full-length Gloom in early 2018 — the latter issued as a strictly limited digipak of fifteen copies via Silentium in Foresta Records. The music draws on raw, atmosphere-heavy DSBM traditions and has appeared on national scene compilations such as Coletânea de DSBM Nacional.

Monster Coyote were a power trio who built a following in the South American stoner/sludge underground with their debut album The Howling (2012) and the follow-up Neckbreaker (2015), the latter earning positive notices beyond the region. Active until around 2018, the band performed at major Brazilian festivals including Festival DoSol and toured across South America before splitting up.

Monster Mash channel the early German speed/thrash scene — citing Vectom, early Blind Guardian, and Iron Angel as touchstones — with high-energy performances anchored by the versatile vocalist Lion. The band surfaced with the demo He Gambled with Satan and Lost, a three-song statement that mixes traditional and extreme thrash with tight cohesion.