Buff boxing kangaroo Roger dies of old age

Roger crushes a can.

Roger crushes a can.

Roger, the beefcake boxing kangaroo with pecs to rival Arnold Schwarzenegger, could crush metal bins with his arms.

On Saturday Roger's strength finally failed, and he died at the ripe old age of 12.

The monster male roo, who weighed 89 kilograms and stood over six feet tall, became the darling of the internet when a picture of him crushing a metal bucket like a paper cup went viral in 2015.

Roger, in imposing mood.

Roger, in imposing mood.

His death has sparked an outpouring of grief from his 1.3 million Facebook and Instagram fans.

"He always brought a smile to my face. Such a proud strong boy," Australian singer Natalie Imbruglia wrote.

Roger was just a tiny joey when his mum was killed by a passing car near Alice Springs in 2006.

His luck turned when a man named Chris Barnes drove by and gave him a new home.

In a tribute video posted to Facebook, Mr Barnes said Roger inspired him to build The Kangaroo Sanctuary to house the rapidly growing roo and "a couple of his wives".

That's an Alpha male stance, for sure.

That's an Alpha male stance, for sure.

"Roger was our Alpha male for many years, and he grew up to be a Kangaroo that people all over the world have grown to love as much as we love him too," he said.

"So we'll reflect on his life today and for many years to come. We've laid him to rest out here so he can always been with his family."

The sanctuary often posted pictures and videos of Roger demonstrating feats of strength, kickboxing and flexing his pecs to display his dominance.

However Roger mellowed in his old age, becoming less aggressive and letting Mr Barnes and other sanctuary staff pat him.

“He lived a lovely long life and was loved by millions around the world. We will always love you and miss you Roger," Mr Barnes said.

Australian Associated Press