Roger, a kangaroo with rippling muscles who hopped into the heart of the internet in 2015, becoming a beloved meme, has died. He was 12.

The Kangaroo Sanctuary, in Alice Springs, Northern Territory, Australia, where Roger lived, wrote on Facebook on Saturday that his cause of death was "old age."

"He lived a lovely long life and was loved by millions around the world. We will always love you and miss you Roger," The Kangaroo Sanctuary wrote.

Roger became a meme in 2015 after images of him crushing a metal bucket went viral. Photos of Roger looking buff and tough also made the rounds, cementing his internet fame.

Roger, the "buff kangaroo" who became and internet sensation, has died at age 12. The Kangaroo Sanctuary via EPA

Dr. Chris Brown, an Australian veterinarian who found Roger as a joey after the marsupial's mother was killed by a car in 2006, according to the Guardian, posted on Facebook on Sunday.

"Goodbye Roger. Sadly, the world’s most famous kangaroo has passed away at the grand old age of 12. And while your flexing may have got the headlines, it was your presence and personality that most impressed me," Brown wrote.

Brown also revealed that Roger suffered from arthritis in his old age.

"It was an honour to meet you and help you manage your arthritis; a disease that was a trade off for a life well lived. And live (and love) you did. Right until the end," he wrote.

Australia's official Twitter account also mourned Roger, calling him an icon.

"Remembering Roger, the world’s most buff kangaroo, and a true icon of [the Australian outback]," the tweet read.

On Sunday, The Kangaroo Sanctuary posted the last photo taken of Roger, lounging before a big meal, muscles still perfectly flexed.

"The last photo of Roger we took was just a few days before he passed. He was relaxing before a big feed," the post read. "Thank you everyone for your beautiful messages about Roger. He was so well loved by you all."

In his post, Brown mentioned that Roger is survived by "multiple wives" and thanked him for helping spread "understanding and appreciation of our national animal."