A couple of questions come to mind while watching Alex Boone tower over most of humanity as he sweats, swears and mauls his way through an NFL practice.

Does this guy own a giant ax, and where is Babe, his big blue ox?

For the offensive line to take the next step in 2016, coach Mike Zimmer demanded an infusion of mental and physical toughness wrapped in spit, vinegar and general nastiness. General Manager Rick Spielman responded by bagging Boone as the team's prized free-agent acquisition and Paul Bunyan-sized left guard.

Listed at 6-8, 310 pounds, Boone is bigger than 6-7 left tackle Matt Kalil. Better for Kalil, too. In fact, coaches say Boone's aggressive nature and outspoken personality have been infectious and helpful to a unit whose passive mentality cost former line coach Jeff Davidson his job after last season.

"Absolutely, Alex has had a big impact on changing the attitude," offensive coordinator Norv Turner said. "Up front, it's a lot about attitude."

When the Vikings settled on their starting five linemen, Kalil and Boone were on the left side, Joe Berger at center, Brandon Fusco at right guard and Andre Smith at right tackle.

Zimmer wants to see more progress when the regular season starts on Sunday, but he said he's happy with where the line is compared to where it was before Boone and new line coach Tony Sparano upped the ante in terms of aggression. Last year, the Vikings ranked 31st in sacks allowed per pass play, and lacked consistency in the run game despite ranking fourth.

"Zim challenged us to play more physical," Sparano said. "When you watch us in practice, we're playing against a very good defensive front that has made each guy better. But we've also gotten better at coming out and pushing the pace of practice rather than waiting to let the pace be pushed on us."

Boone's personality made him an instant leader, which is rare for a newcomer, even a veteran.

"He takes charge of the room," Sparano said. "His personality is very aggressive. He likes to attack things. He's not afraid to get into confrontations.

"I'd say his demeanor is rubbing off on a lot of guys. I'm hearing guys talk that I didn't hear talk before."

The talking stops Sunday when the revamped line is joined by running back Adrian Peterson in live action for the first time. Together, they'll need to set the tone for a team that's scrambling at quarterback.

"I can't wait to play with Adrian Peterson," said Boone, "and kick some …"

He didn't say butt.