Scientists have long pointed out the extraordinary scale of genetic differences between octopuses and most other animals. But the creatures also had the power to inspire terror in Victorian Britain.
Adults paid sixpence and the under-12s got in for half-price. Queues spilled into the grounds of Crystal Palace in autumn 1871 as the public waited for a glimpse of the biggest sensation in London.
It wasn't a freak show or a demonstration of the latest technology that attracted them, but a creature that had been around for millions of years, living in every ocean.
An advertisement in the Times informed potential visitors to Crystal Palace's new aquarium the chance to view "thousands of living creatures of the sea", but what everyone wanted to see was "the wonderful Octopus, or Devil Fish".
The eight-legged, boneless cephalopod mollusc (not a fish) had become a literary sensation, with the publication of Victor Hugo's novel Toilers of the Sea five years earlier. It featured a fight between a fisherman and a giant octopus. Hugo claimed the animal, well known previously to seafarers but little seen by anyone else, drank the blood of its "victims".