Now touring behind its fifth album, The Hunter, Atlanta’s reigning prog-metal act stomped its way to critical-darling status by virtue of more than just formidable song sorcery. One can feel writers’ glee by reading reviews of the band’s sludgy, heady, unrelenting approach to rock that manifests in album titles like Leviathan and Blood Mountain.

“The four of us have this really bizarre chemistry where the riffs and the thoughts and the ideas, the lyrical process, it’s out there,” said Troy Sanders, bassist and most guttural howler. “It’s bizarre.”

Each new Mastodon disc warrants extensive explanation to the press of its involved themes and twist-filled plots, which Sanders said can be tiresome.

“We get our ideas lined up for the right answers in advance, because we know we’re going to get asked,” he said. “Thankfully, this album is more of [where] each song has its own story.”

Unlike its thematically rigorous predecessors, The Hunter pinballs across a morbid gamut of topics, including backwoods meth heads, bumping uglies in zero gravity and the death of Mastodon’s accountant’s wife. This marks a major departure from its last album, Crack the Skye, which detailed the journey of a paraplegic who astral-traveled his way into the body of Rasputin before running into the devil somewhere in the ether.

“We’re most excited about our most recent material,” he said, “but we also realize that we’ve built up loyal fans over the last 12 years and five albums’ worth of material.”

On Saturday, fans can check out the group’s contribution to Record Store Day: a cover of The Flaming Lips’ “A Spoonful Weighs a Ton,” which occupies the B-side of the Lips’ 7-inch re-release of that Soft Bulletin song.

“It’s dreamy, it’s got the heaviness to it — it just had the characteristics of a song that we felt Mastodon could do a decent job covering,” Sanders said. “We hoped to do a classy and respectful job.”

10 Awesomely Named Mastodon Songs

1. “Aqua Dementia”
2. “Blasteroid”
3. “Curl of the Burl”
4. “The Wolf Is Loose”
5. “Stargasm”
6. “The Octopus Has No Friends”
7. “Bedazzled Fingernails”
8. “I Am Ahab”
9. “Blood and Thunder”
10. “Mother Puncher”