Things can get downright deadly when male kangaroos fight over mating rights. With their gigantic feet, these "boomers" deliver kicks that can crush bone... and even kill their opponents.
Kangaroos are vegetarians, but they can be fiercely competitive when it comes to courting females.
And when they combat each other, feet are their weapon of choice.
They're armed with extremely muscular hind legs and enormous feet, which help them to execute broad jumps with every hop.
This Bigfoot can cross the vast reaches of the Australian Outback with ease, at peak speeds of almost 45 miles an hour.
But one thing can stop this speed demon in his tracks: A potential mate.
For days during mating season, a male kangaroo, also called boomer, will follow a female.
He shadows her every move.
But there are plenty of boomers out there, and fights between them will break out often.
And that's when the weapons are unleashed.
It starts with a quick right jab...then descends into an all-out brawl.
This is not just boxing; it's more like ultimate fighting.
A favorite tactic: using the forepaws to grip the opponent and then quickly kicking with their huge clawed hind feet.
It's a move that can crush bones, disembowel the opponent...even bring death.
Fortunately, a referee breaks up this match before it goes too far.
But he can't stop the next generation of Joeys from trying some of their own shadow boxing.