If you're adventurous enough to snorkel or dive in the waters around Western Australia, you might come across a creature that shoots purple dye and has ears like a rabbit.
They might be a snorkeller's delight, but most people only come across sea hares when they are washed up dead on the beach.
Masses of the creatures line the shores of some beaches in WA's South West every year between January and March.
"They're just a natural part of the environment and I think we're really lucky to have them," said Dr Lisa Kirkendale, head of aquatic zoology and the curator of molluscs at the Western Australian Museum.
Slimy, stinky, and potentially toxic to canines, the first sightings of their bodies prompt warnings to dog owners to stay alert near the water's edge.
Margaret River veterinary surgeon Dr Amy Forsythe said she sees about four or five cases of dogs getting sick after eating sea hares every year.
She said beaches at the nearby town of Augusta was was littered with large numbers of the creatures each year.
"[Last year] Augusta looked like it was just a sea hare party. Not much beach left without them on the ground," said Dr Forsythe.
"We're seeing more and more every year."
Toxins cause tremors, overheating in dogs
Dr Forsythe said every dog she treated for sea hare exposure had survived, but she had heard anecdotally of dogs that had died.
Ingesting the sea hare toxins could cause seizures in dogs, said Dr Forsythe, as well as overheating.
"Most of the time when I see them presenting, they can't really walk and they'll have full body tremors," she said.
"With therapy, they usually recover quite well."
Dr Kirkendale saw a different side of the sea hare.
She acknowledged the toxicity risk presented by the creatures, and understood the sight and smell of their bodies could be unpleasant.
But she said Australia was lucky to have sea hares in its oceans.
"They're pretty cute," said Dr Kirkendale.
"They're related to sea slugs, and they're also related to squid and clams and other marine shells."
Creatures with wings and purple dye
Dr Kirkendale said sea hares swim with "wings" called parapodia and can release a vivid purple dye, similar to the way that a squid expels ink.
They also have a life cycle of just one year.
Dr Kirkendale said Australian oceans were also home to the world's largest sea hare known as Aplysia Gigantia, a model of which was on display at the Western Australian Museum.
She said the number of sea hares annually washing up on beaches depended on the success of their breeding season.
