It was stardom from three "Free Willy" movies that set the campaign in motion to reintroduce the six-ton orca to the open sea after he spent much of his life in captivity.
But six weeks after he was released from his pen in Iceland, his keepers are worried that Keiko is becoming a victim of his own celebrity and are begging people to leave him alone, so that the $20 million project to return him to the wild can continue.
"We are just trying to get people to leave Keiko alone so he can decide whether he wants to stay here," says Colin Baird, a 35-year-old animal trainer from Canada. "All the distractions from boats and people are keeping him from doing what he should by hunting food."
Keiko seems content in the fjord in western Norway, where he ended up last weekend after swimming 870 miles in what many said was a search for human companionship.
On Thursday, he swam under an empty, moored yellow boat and used the barnacles on the bottom to scratch his back, then his white belly.
He surfaced, exhaled from his blowhole and peered around as if to check whether his fans had arrived. He let out a cry and was answered only by the bellow of a nearby cow.
The previous evening, Keiko was overrun by fans, including 16-year-old Mona Lindkvist.
"It was silly to set him free. He wants to be with people," said Lindkvist, who rowed for hours in a small boat to pet him near the floating dock at the Skaalvik Fjord in the township of Halsa.
"He feels kind of like hard plastic with something soft under it. I want to swim with him, but my parents won't let me," she said.
Lindkvist was joined by about 70 people standing on the flimsy floating dock. Keiko lay placidly in the water, surrounded by a dozen boats. Obligingly, he edged closer to the dock and seemed to wave with a fin, occasionally "talking" to people in chirps.
A father on a boat held his daughter by the belt as she hung upside-down trying to reach Keiko. Some whistled or did their best to imitate whale calls.
"It would be wonderful if he stayed here," 13-year-old Tanja Kristin Haugen said.
Keiko — the name means "Lucky One" in Japanese — was captured near Iceland in 1979 when he was 2 years old. After the "Free Willy" films, he was rescued from a Mexico City amusement park in 1996 and brought to the Oregon Coast Aquarium.
Keiko was airlifted back to Iceland in 1998 and was taught to catch fish so he could be released into the wild.
As Norwegians ponder what to do about Keiko, Baird and his colleague Fernando Ugarte, a marine biologist from Mexico City, tour local schools and explain why Keiko must be left alone.
At the Blakken Primary School, Ugarte, who speaks Norwegian, asked who among the 31 children had seen Keiko. They all raised their hands.
He told them that Keiko, who needs more than 110 pounds of food a day, looks in good shape but is getting too little food and too much attention.
"He is hungry. He wants to find food but he loves people. If you want to help him, don't spend so much time with him," Ugarte said. "If just one person wanted to sit on him or pet him or swim with him, it would be OK, but then everyone would want to do it ... and Keiko would be too busy to eat."
But Keiko is one of the biggest things ever to happen in this town of 1,750 people, a mix of rolling farmland and small mountains 250 miles northwest of the capital, Oslo.
Norway and the groups behind the campaign to free Keiko, the Ocean Future Society and the Humane Society of the United States, have discussed leading the whale back to Iceland, Baird said. Some have suggested leaving Keiko in a remote fjord and feeding him there.
For now, they are hoping that, if left alone, Keiko will set off in search of food, possibly even finding the pod of killer whales he briefly joined after being freed in mid-July.
Experts also warn people to be cautious because of Keiko's size and strength. Earlier in the week, Keiko knocked three people into the water because the toy inflatable boat they were in "looked a lot like his favorite toy," Baird said.
By midmorning Thursday, Keiko's dock was slowly filling up with people. Lars Terje Hoaas, 37, said Keiko "nodded as if he wanted to say thank you" after someone fed him.
Looking tired, Baird sighed.
"The amount of human contact has been a bit of a setback. It is a bit frustrating when people don't listen," he said.