Australia's most dangerous creature isn't what you think it is.

Australia's most dangerous creature isn't what you think it is.

A warning has been sent out to parents after a young girl unknowingly took home a deadly marine animal that was hiding in a shell on a Western Australian beach.

After a day of playing on Coogee beach, south of Perth, the girl collected some shells to take home.

As her aunt was washing them she discovered a blue ringed octopus was hiding in one of the shells.

Coogee Beach WA Surf Life Saving Club uploaded photos of the dangerous creature to Facebook as a warning for parents to keep an eye on what their kids are doing at the beach.

“A young girl was at the beach this morning in front of our club building sandcastles and collecting shells,” the post read.

“Lucky her Aunty was cleaning the stash of shells when they got home as this critter emerged.

“They look beautiful....but a bite can be deadly.”

Blue ringed octopuses are a highly venomous species and are usually found in tide pools and coral reefs.

The octopus gets its name for its circular, iridescent blue markings, which are usually only displayed when the animal feels threatened and is about to release its poison.

According to the Australian Institute of Marine Science, the chemical the octopus releases, which is called tetrodotoxin, aims to paralyse its target.

Two deaths are known to have occurred from a blue ringed octopus bite in Australia, with many more coming very close.

Death usually occurs as a result of lack of oxygen as the toxin paralyses the muscles but leaves the victim fully conscious.