By Liam Miller @tweetliam
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Videographer / Director: Laurentiu Garofeanu
Producer: Liam Miller
Editor: Ben Churcher
The fearless bear handler goes for dip in a swimming pool with 16-year-old polar bear Agee, where the two enjoy a watery cuddle together.
Back on dry land, he wrestles with the 60-stone (800lb) beast in her enclosure and bravely lets Agee clamp her huge jaws around his head.
With their incredibly intimate bond, Agee even bear hugs owner Mark as she rears up on her hind legs to over seven feet.
And when the wrestling has tired both the animal expert and the his amazing pet out, they both take a nap together inside Agee's enclosure.
"If anyone else tried this they would end up as Agee's dinner," said Mark. "The only people in the whole world she likes are me and my wife.
"I have worked with bears in this way for over 40 years, so I can read Agee's body language and know how to behave safely around her.
"But Agee is the boss and it's her rules that count."
Mark, 60 and wife Dawn, 49, from Abbotsford, British Columbia (BC), Canada, train the polar bear - one of the world's largest land predators - to star in high-budget TV adverts and films.
Mark and Dawn took Agee on when she was just six weeks old.
With links to Hollywood through previous work with animals, Mark was approached by director Fraser Heston - the son of screen legend Charlton - 16 years ago.
Heston needed a polar bear cub for his forthcoming film 'Alaska' and Mark found Agee - a surplus cub at Kolmarden Zoo, Sweden.
Mark and Dawn went through a lengthy application to show they had the facilities to care for her.
After being approved they transported the tiny cub to Canada.
"She lived inside our house for the first few weeks and we hand-reared her," said Mark.
"But it got to a point where she was so big we had to move her outside into her own enclosure."
Now Agee spends her time living in her new home on rented land near Mark and Dawn's place in Abbotsford, and on the road working on TV and film sets.
At home, Mark enjoys 'playtime' with her.
"Earlier in the morning she's more playful and relaxed and she lets me roll around with her," he said.
"We wrestle for fun and sometimes we fall asleep on the grassy lawn together. It's a great way to unwind after a bad day."
"I feel pretty privileged to be able to nap with my head resting on a fully grown polar bear."
In the afternoons, when they are preparing for filming, Mark 'works' Agee.
She performs a variety of commands in exchange for her favourite reward foods - doughnuts and cookies.
On cue from Mark, she rears up on her hind legs and will even pretend she's roaring when instructed to 'smile'.
"She doesn't actually roar but she makes the action," said animal handler Dawn. "Film crews will later add in the sound of the roar if that's what they need for their production."
Agee will also lay down, crawl and sit up in return for tasty treats.
"She loves her work," said Mark. "Polar bears are extremely intelligent animals and you can see she gets enjoyment out of being stimulated through her activities.
"She could never have lived in the wild so it's important to us that we keep her active and thinking.
"That's why I like swimming with her and playing on the lawn."
In the evenings Agee is fed on mountains of protein-rich salmon, chicken or other meats, along with carbohydrates she gets from high-quality dog food and vitamin supplements.
"In her natural habitat she would be eating seal but we can't buy that so we have to try and replicate a fat-rich diet," said Mark.
"Because polar bears scavenge in the summer - when they are off the sea ice and on dry land - they have very adaptable diets."
In addition to having favourite snacks, Agee also seems to have favourite types of friends, and often prefers men to women. "She gets very jealous of other women talking to Mark," said Dawn.
"She's happy with me doing it but if any other women are around she gets very possessive of him."