A row has broken out over the fate of a rare six-legged octopus pulling in the crowds at Blackpool Sea Life centre.
Peta says Henry has become a "sideshow freak"
Henry the "hexapus", which experts say probably has a birth defect, was found in a lobster pot off the coast of Anglesey, north Wales, two weeks ago.
Animal rights campaigners say Henry's new home at a Blackpool exhibition called Suckers is cruel and has turned him into a "sideshow freak".
Centre bosses however, said the octopus "seemed happy" in his tank.
The People for the Ethical Treatment of Animals (Peta) criticised the centre in an open letter from special campaigns manager Anita Singh.
In it, she urged aquarium bosses to spare Henry from a "life in captivity" and said supporters had contacted them calling for his return to the sea.
Ms Singh said: "We are hearing from our members, supporters and the public, whose hearts are going out to this animal. They want to see him returned to the ocean.
"Octopuses are intelligent animals who feel pain, have proven problem-solving abilities and value their lives as much as we do ours.
"Keeping Henry in an aquarium as part of an exhibit is alien to the life he knew in the sea before being caught. It is exceedingly cruel to turn this wild animal into a side-show freak."
Octopuses need subdued lighting and exposure to flash photography can prove fatal, and Ms Singh said Peta was worried about the crowds attracted by the exhibition.
Carey Duckhouse, the centre's display supervisor, said it would now be impossible to return the octopus to the wild.
"He probably adopted the lobster pot he was found in as his den and unfortunately he was taken out of it," said Mr Duckhouse.
"It is highly unlikely we could return him to the spot we found him.
"He is an invertebrate, soft bodied and putting him back in the coastal waters of Anglesey wouldn't be ideal, it would be a shock to the system, they are very delicate animals and it's very unlikely he would survive.
"He is kept in a large tank, they have subdued lighting and no one can use flash photography, and he is eating which is a very good sign.
"He had a whole hermit crab yesterday."
Mr Duckhouse said staff played with the creatures and provided toys to stimulate them and keep their environment interesting.