Alun-Wyn Jones expects to encounter a 'wounded animal' when Wales tackles Australia at the Millennium Stadium on Saturday night.
While Wales looks to end its autumn Test series with a third successive win, Australia is facing a salvage job.
Having set their sights on a successful Grand Slam mission by defeating England, Ireland, Scotland and Wales, the Wallabies could head home reflecting on a meagre 25 percent success rate.
Their 18-9 victory at Twickenham seems an age ago, and they have arrived in Cardiff following a 9-8 loss to Scotland, Australia's first in that fixture since 1982.
But Wales lock Jones is braced for a fearsome challenge in all departments.
"They will most definitely be like a wounded animal," he said.
"It will be a completely different ask for us, especially given the way Australia are playing in the back-line, the way they are constructing their moves and playing rugby."
"They are another major southern hemisphere side, but they will pose a completely different challenge."
"People say their attack hasn't been great from the ball they've been getting, but their backs are flourishing off whatever ball they get."
"We will see if we can maintain the momentum we have picked up after beating Samoa and Argentina, and this will be the telling of how far we have come from last year's autumn series."
Wales complete its preparations at the Millennium Stadium on Thursday, hoping that an injury cloud over skipper Ryan Jones clears.
Jones, it is understood, has taken only a limited part in training this week.
If he was to be ruled out, then flanker Andy Powell could realistically expect a move to No.8, with Jonathan Thomas starting in the No.6 shirt and winning his 50th cap.
One area Wales will look to dominate is the lineout, where Jones and his second-row partner Luke Charteris enjoyed a 100 percent success-rate against Argentina.
And Jones is quick to deliver praise in 6ft 9in Charteris' direction.
"He is such a big target," said Jones. "It's silly not to throw to him, which is why he was used a lot last weekend."
"He's also making up for what people said he has lacked in the loose in the past. He is at the forefront of a lot of things in the game."
"He is going to be physical, he's over 125kg and he can jump, catch and pass."
"He's a clever guy as well, he's a great athlete and it is great to have someone like him coming along. It is good to have him there."