Yesterday, the presenter was happy to pose with his Muppet-self, looking a little embarrassed. "You're a good-looking fella," the real Sainsbury laughed.
The Muppet was made in New York by Disney's official Muppet makers, The Muppet Workshop.
It came about after Close Up producer Chris Lynch, a puppeteer, travelled to the United States for a story about the upcoming Disney movie The Muppets.
The story airs on TV One tonight, when Mark Muppet will also make his television debut.
"[Chris] came in all excited, saying, 'They want to make a Muppet of you'," Sainsbury said.
"I thought he was joking."
Sainsbury said that when growing up, he had enjoyed watching The Muppet Show and was happy to know it was still a favourite today.
It was somewhat odd to be turned into a Muppet, he said, but it was something unique and he would therefore embrace it.
He was, however, preparing for the jokes.
"You just know you're gonna get a lot of, 'Yeah, I knew you were a muppet' or 'Which one's the Muppet?'
"I mean, it's true that I've been called a Muppet before. But I've never actually been immortalised as one," he laughed.
"We get to do and see all sorts of strange things in our job, but this one is pretty well up there - and you must be prepared to put up with all the teasing."
Mark Muppet will make his first public appearance at the Starship Foundation film premiere for the Muppet movie on Sunday, at the Event Cinemas in Newmarket, Auckland.
All funds raised will go towards the rebuilding of the medical specialties and neuroservices unit at the Starship children's hospital.
The Muppets opens in New Zealand on December 29.
* For more details on the Starship Foundation events see starship.org.nz/events