But she liked to play with people, have them pat her and show off her ball handling skills.
"She would nibble your toes," says Opononi publican Ian Leigh-McKenzie, who was a boy at the time.
As summer heated up, so did Opo-fever. Cameras whirred and clicked. Documentary footage shows children holding hands in a ring as Opo leaps in and out. She learnt to balance a ball - sometimes a beer bottle - on her nose and toss it high. The consummate performer would also turn over, roll the ball along her belly and flip it up with her tail.
Among books memorialising her, possibly the hottest off the press in 1956, was Avis Acre's The Gay Dolphin of Opononi (no, not about a dolphin that swam for the other team). The late writer Maurice Shadbolt based his novel This Summers' Dolphin on the Opo phenomenon.
Pioneer New Zealand filmmaker Rudall Hayward made The Amazing Dolphin of Opononi, one of several documentaries about Opo shown worldwide. A poppy little folk song called Opo the Friendly Dolphin mooned about "fishy back rides and swishy tides".
As the throngs came that memorable summer, locals grew increasingly concerned about the dolphin's safety, especially after reports her fin had been winged by a potshot.
A special protection order for Opo was to become law on March 8, but on that very day the dolphin didn't arrive at the beach as usual. Two days later the people's playmate was found dead at nearby Koutu.
She was buried with full Maori honours outside Opononi's RSA Hall. Some Maori considered her to be an incarnation of Kupe, the great navigator and first to discover Hokianga
The magic summer was over.
