Brian Posehn is built for comedy — by which I mean the guy, with his beer belly and bulbous nose, pale skin and balding head, looks like he better be funny, or some jerk’s going to kick sand in his face.

Onscreen and onstage, in a pile of television appearances from "Seinfeld" and "Just Shoot Me" to Conan O’Brien’s late-night show and "The Sarah Silverman Program," he’s honed a persona as a semi-alienated outsider, compensating for frustration with comic retaliation.

But despite the fact that the 6-foot-7 Posehn is one of the world’s biggest heavy-metal fans, depicts himself on his most recent album cover as a Viking-like marauder standing triumphant over the severed heads of the comic competition, and has an album titled "Live In: Nerd Rage," Posehn is, by his own admission, "nice." (Check him out on Twitter: twitter.com/thebrianposehn.)

His routines bear that out; they’re more likely to turn on sardonic observation, with a touch of acute nerd majesty, than go-for-the-jugular put-downs.

He’s just as likely to mock himself as anyone else: "I look like I’m … made of farts," he told a huge crowd at Coachella … "like a bunch of farts put a people costume on and went, ‘Let’s go out to dinner tonight!’" (He also, accurately, has compared himself to Beaker on "The Muppet Show.")

"I don’t think I’m one of those comedians who’s angry at the world," he said. "My comedy comes from my spin on things."

The fortysomething comic says he’s been a metal fan for a very long time.

"I was drawn to it by the theatrics," he explained. "I like the aggression, but I’ve never been an aggressive person."

Don’t expect Posehn to be too sedate: Onstage, if you pulled the expletives out of his routine, it would be only 75 percent as long.

But then again, you might expect that from a guy who says he hasn’t changed much from his days as a teenage metalhead and named his new comedy album, released in April, "Fart & Wiener Jokes."

"There is a reason I called it that," he said. "The record sort of came from me making fun of myself. I’m one of those self-deprecating comics. I always say, ‘Take off your thinking caps — it’s about to get stupid in here.’ But it’s not all juvenile."

In fact, a new generation is about to take up the juvenile torch in the Posehn family, as the comedian is stretching to accommodate a new role: dad.

POSEHN called up TGIF on Monday from his home in L.A., where he lives with his wife and 15-month-old son, saying he was working on new jokes for his stand-up act.

"I’m a new dad now. My life and my stand-up act are changing," he said. "A big chunk of my act is all brand-new."

The gist of it is that while Posehn is "that guy" — "I’ve never grown up," he said. … "I’ve really never changed. I like metal music. I like comic books" — he is trying to find a way to stay that guy while still being a good dad.

"I’m still trying to be that 15-year-old metalhead, but still be grown up," he said. … "When can I share my passions with my kid? It’s kind of too early to turn him on to Slayer or ‘Night of the Living Dead,’ but what about Weird Al?"

There’s another sense in which Posehn is "that guy": He’s the guy you recognize as soon as you hear his voice or see his face. More than 2 million people have watched his music video, "Metal by Numbers," which transports him into a fantasy garage as the frontman of a painfully predictable band, and doubles as an instructional tool for aspiring headbangers. (Sample lyric: "Cookie monster vocals or yell like a wookie!")

Now, he’s nearly always working, and he’s no longer an unknown quantity.

"’Just Shoot Me’ was pretty much the most mainstream thing I’d done," he said. "Now there are all these things. … With the voice work, the YouTube presence … I’m recognized for all of it," by different people.

Posehn didn’t have to be asked if he was looking forward to a Hawaii trip; he broke in to say so.

"I meet my doppleganger in every city I go to," he said. "I hope the people who identify with that will come out."