DOG owners should keep their pets away from sea hares after one washed up on a Mandurah beach this week.
Mandurah residents were left puzzled after a photo of one the creatures was posted on social media yesterday.
The sea hare was found on a Dawesville beach.
Department of Fisheries senior communications officer Craig Sinclair warned the creature could be dangerous to dogs.
“They are not uncommon on the beaches at this time of year,” he said.
“They present in a range of colours from black/purple to mottled green.”
The sea hare is a mollusc, like snails, octopus and scallops.
When it is threatened it emits a toxic residue that is poisonous if it licked or chewed.
The giant sea hare can grow up to 70cm in length.