The photographer at the centre of an international row over the ownership of a selfie photograph taken by a monkey in Indonesia says he will vigorously resist the latest challenge to its copyright.
But David Slater said it took three days of hard work to get the photo.
He said that money accrued from its re-use around the world belongs to him.
"It took three days of blood, sweat and tears to get the selfie in which I had to be accepted by the group of monkeys before they would allow me to come close enough to introduce them to my camera equipment," Mr Slater said.
"The trouble is, other people are trying to steal the ownership rights and I will fight to resist that."
'Breach of integrity'
The selfie of the crested macaque money has been widely distributed around the world by numerous outlets, including Wikipedia. They and other outlets argue that the copyright to the images cannot be owned because they were taken by an animal rather than a person.
Mr Slater says that he had to earn the trust of the monkeys over several days before venturing close enough to get the selfie.
Earlier this week, activists from the People for the Ethical Treatment of Animals (Peta) filed a lawsuit in San Francisco seeking permission for it to administer all proceeds from the photos for the benefit of the male monkey, which it identified as six-year-old Naruto.
"If Peta US prevails in this lawsuit, it will be the first time that a non-human animal is declared the owner of property, rather than being declared a piece of property himself or herself," Peta Director Mimi Bekhechi said.
But Mr Slater said that the attitude of Peta and Wikipedia "stinks" and is a flagrant breach of his artistic integrity.
The monkey was intrigued by its reflection in the camera and took several mug shots, Mr Slater says.
He argues that it took "much time and more perseverance" to get the selfie, taken on a reserve on the Indonesian island of Sulawesi in 2011.
He had to spend several days with the monkeys so that they became relaxed in his company. He said he only managed to get the photo by setting up his camera on a tripod with a cable release switch which the monkey in the famous selfie pressed.
In addition, he had to make sure that the light and contrast switches on the camera were properly set - work which he says is more than sufficient for him to claim copyright of the photos.
"I was lying down at the time with at least two macaque juveniles on my back and nursing a few bruises from a male who had whacked me several times all over in the belief that I was a challenge to his females.
"So please don't tell me these photos are not my property."