Unbelievable moment zookeeper is attacked by a lion but saved by a lioness

Warning: This article contains a video which some readers may find distressing.

The shocking moment a zookeeper is attacked by a lion and then rescued by unexpected hero could be the most unbelievable footage you will watch today.

In a video that went viral last year, people can be heard gathering around a lion enclosure that is thought to be at a hotel in Las Vegas.

Footage from a bystander shows two zookeepers also in the enclosure with the big cats, but no one could have predicted what happened next.

After it resurfaced on Reddit, the terrifying video quickly gained a lot of attention online.

Take a look below:

It begins with the two zookeepers in the lion's pen observing a male lion and a lioness who are both seemingly lying calmly on the ground.

One of the keepers is tasked with keeping his eyes on the male lion - something that nearly turns into a fatal mistake.

When the camera pans away for a couple of seconds, mayhem erupts as the tourists can be heard gasping in shock.

The camera rapidly turns back as the lion goes for the keeper.

Terrifyingly, the big cat manages to get him to the ground as it attempts to clamp down on his leg.

His colleague rushes over to try and assist, but it's the lioness’ quick reactions that ultimately helped both men escape unharmed.

Reddit

Rushing over, she falls on top of her mate and bites at his tail as he gets up, before eventually managing to get herself between him and the zookeepers, guiding him away from them until he runs off.

Redditors were quick to take the side of the lion, with one writing: "His posture, his body language. It says 'Challenge' and the lion took it as such.

"I won't say he deserves to die, but I believe the lion should be forgiven, and the man never allowed in an enclosure with a wild animal again."

Reddit

"Dude was staring down the lion. Don’t stare wild animals in the eyes. It’s never not a threat," a second added.

Meanwhile, a third took aim at the zoo itself, saying: "No zoo in their right mind would let workers or anyone be that close to lions. These people are obviously not trained properly in animal care."

Others took a more light hearted approach and saw the funny side of the situation that had a happy ending.

"I think I heard the lioness say 'I can't take you anywhere,'" one commenter quipped.