Autumn temperatures may finally be creeping into Houston at last, but Portland's Red Fang promises to work up one last sweat in the city on Sunday when the shaggy rockers roll into Fitzgerald's.

The band had too much fun hitting the road this summer to close the books on it just yet. Red Fang played a long string of dates in Europe, including festival stops at Denmark's Roskilde and Germany's hallowed Wacken Open Air, among others. Memorable as that tour was, the highlight of the band's season came in June, when Red Fang was hand-picked by Metallica to perform at the inaugural Orion Music + More festival in Atlantic City.

"Orion was an amazing festival, but I honestly don't remember too much about it because right before we played, James Hetfield came over and introduced himself to us," says Red Fang bassist/vocalist Aaron Beam. "He is such a huge influence, at least on me, that I went into kind of a daze and the show was a bit of a blur."

Hetfield's influence shines through on riff-heavy tunes like "Wires" from the band's latest album, 2011's Murder the Mountains. Not unlike the band members themselves, Red Fang's sound is heavy without being obese, and pleasantly fuzzy.

Though they're veterans of the metal festival circuit, much like their kindred Texas spirits in the Sword, they're not quite as firmly entrenched in the world of pentagrams and death as one might initially expect.

Elements of Soundgarden and the Melvins are as much in evidence in their music as metal forebears such as Black Sabbath. Rather than some slick metal knob-twiddler, the romping, stomping Murder the Mountains was produced by Chris Funk, the multi-instrumentalist famed for his work with Portland indie-rockers the Decemberists.

"We were a little nervous about (working with Funk) at first, but we are not like a technical death metal band that needs a certain type of production," Beam says. "Producers and engineers often get pigeonholed as only doing pop or indie or folk records or whatever, but those classifications are bullshit.

"If someone has a good ear and can make a great sounding record, it doesn't matter what types of recordings they have done in the past," he adds.

Red Fang's occasionally bluesy, often swampy riffage has led to many fans and critics tagging them as a stoner-rock band, a label Beam neither agrees with nor completely rejects.

"If someone likes stoner rock and thinks we sound like stoner rock, that's fine," he says. "People hear all kinds of different things depending on their frame of reference. I don't think of us as stoner-rock, but I don't mind if someone else does."