Mastodon vocalist and guitarist Brent Hinds both played guitar and sang in Portuguese on the new Fantasma track "Morder para Sangrar." You can check that out above alongside a pretty fun video.
As for a new Mastodon album, the band is working through ideas at the moment and doesn't have a definitive timetable (that we know of) just yet. Mastodon also has a new song with Neurosis frontman Scott Kelly possibly titled "Fallen Torches" that was recorded to originally be out in January 2019. The band couldn't get the song out the door in time, so as it stands right now, it's just sitting around.