The All Blacks' new 140kg weapon set to be unleashed on Wallabies

He's the 140kg wrecking ball who threatens to turn the Wallabies' Bledisloe Cup dream into a nightmare.

And monster prop Pasilio Tosi perversely credits COVID-19 as his launching pad from an NPC No.8 to an All Blacks cult figure.

After making his Test debut against Fiji in July, Tosi will come off the bench looking to terrorise the Australians at Accor Stadium on Saturday.

The 26-year-old's idol and inspiration Ardie Savea, who hits the scales at some 45kg lighter, is urging Tosi to use his huge frame as the weapon to kill off any Wallabies hopes.

"I want some of those thighs," Savea said sitting next to the powerhouse prop.

"I always try and tell him 'get the ball in your hands' because he's a hard man to stop.

"When we do tackling drills, he lifts me up.

"He's got the heart and size of a bus, and obviously if you know the journey that he's come from, it's a testament to his heart and his family and his dedication."

And some journey it's been.

Tosi was toiling away in the back row in club rugby when the pandemic hit four years ago.

"That lockdown, food was my best friend," said the Rotorua High School graduate.

"It was just making use of my partner's cooking. Yeah, it was good so whatever she cooked, I never said no."

The super-sized Stags forward said to save his rugby career he had no choice but to transition to the front row.

"I made the call, had to talk to my partner as well, and it was kind of just ego," Tosi said.

"An ego thing telling myself that like I didn't want to change from eight, but I still want to have the focus.

"But I knew that it was a good change for me and it would have been a new challenge as well.

"So I feel like if I hadn't have changed, I wouldn't be here at the moment."

Tosi first went from the Stags to the Steamers before earning a Super Rugby contract with the Hurricanes in 2021.

He hasn't looked back.

"It's a huge testament because obviously being a No.8 for so many years and then transitioning to play prop and being an international prop, not many people can do that," Savea said.

All Blacks coach Scott Robertson commended Tosi for making the "big decision" to change positions.

"He's skillful, big, got good feet, understands the game well and he's really hard on his craft," Robertson said.

"He's a Test footballer, he's got the size, he's a unit - he's first to most meals and has got a great sense of humour but when he crosses the line, he can switch.

"So he's a good balance for us."

Tosi admits he's living out a childhood dream.

"It's a huge privilege to wear the jersey that a lot of people would die to wear," he said.

Before the Wallabies have to contend with replacement Tosi, though, they must try to contain an All Blacks outfit hungry to atone for back-to-back Rugby Championship losses to the Springboks in South Africa.

"We're trying to just release the shackles and just play and when you see great All Black teams play, they look like it's just there in the flow state," Savea said.

"So we're just trying to navigate that space, but there's been a lot of energy, and 'Pos' has been part of that in the gym, off the field, on the field.

"Plenty of energy and a lot of excitement."