Is this the original buff kangaroo?
Footage has surfaced of a tall, bulky roo facing off with a film maker from the other side of a tall fence, scratching his belly and flexing his muscles.
The voices of astounded onlookers can be heard in the video in reaction to the giant kangaroo.
'Oh my god… he's like an alien,' one says.
What he definitely looks like is a boxer, and - not surprisingly - he is called Rocky.
Rocky Balboa was a boxer played by Sylvester Stallone in a series of movies.
The video was reportedly filmed at the Louisiana Zoo, in the US.
Video of the muscular roo showing off his well-built upper body, which was posted to Youtube two years ago, resurfaced on the internet recently.
Although the children in the background of the video may be giggling, Rocky is not an animal you would want to meet in a dark alleyway.
Much like the huge kangaroo dubbed Dave, who made international headlines after he was photographed hopping around the streets of Moreton Bay, north of Brisbane, earlier this year
Although Rocky's height and weight are not known, Dave, an Eastern Grey kangaroo, weighed in at 95kgs and about 2m tall.
Another contender for the brawny kangaroo title is Roger, who lives at The Kangaroo Sanctuary Alice Springs in the Northern Territory.
His pastimes include crushing metal buckets with his bare paws, and he boasts a weight of 89kg and height of 2.007m from top to tail.