The strange creature was posted online by a Reddit user who found it on the beach in Broome with his mum and girlfriend.
A picture shows the creature on the sand with mottled-black tentacles with a balloon shaped middle, resembling a head.
Internet users were perplexed by the weird tentacled creature with some speculating what it could be.
One commenter said: “What the heck?”
But eventually people came began to realise and agree on what the creature was.
It is a sea anemone which has been flipped upside down after being beached.
Another commenter said: “The armed anemone. Also called the striped anemone.”
Armed anemone are found in tropical waters off the coast of Western Australia.
They can grow up to 50cm and usually have more colour.
But it could be that the creature was bleached by the sun, some Reddit users speculated.
The creature has a venomous sting that is extremely painful to humans and can take months to heal.
In September another “alien-like” creature was discovered by a British beach goer.
““What the heck?””
Liverpool-born Adam Dickinson, 31, found the bizarre being on a beach in his adopted homeland of New Zealand.
In photos, it appears as a number of purple blobs arranged in a circle, bounded by a sun-shaped ring of white jelly.
The creature was identified by New Zealand’s National Institute of Water and Atmospheric Research as a lion’s mane jellyfish – the world’s largest known species of jellyfish.