GREEN COVE SPRINGS, Fla. – Millions of fans have made the popular HBO series "Game of Thrones" a must-see show. Some of the show's biggest stars aren't people, they're wolves. As a result, real-life wolf-dog breeders are trying to keep up with a newfound demand to own them as pets. But fantasy can be a lot easier to handle than reality.

Wolf dogs are being surrendered when people realize they're much harder to take care of than they thought. A private sanctuary in Clay County is taking them in and trying to keep them alive, but the owners are getting overrun.

John Knight and his wife, Debbie, started rescuing wolves and wolf-dog hybrids a few years ago.

"Our original two turned into 60 over three or four years," John Knight said.

As a result, they created Big Oak Wolf Sanctuary. It's closed to the public and has become a place where many of the surrendered animals are there because of shows like "Game of Thrones."

WATCH: Why age is major factor in allure of owning a wolf

"When they get these animals and expect that, they're in deep trouble. That's where we come in and we are overrun with them right now," he said.

Gabriel is one of the wolf dogs at the sanctuary. Nikki Kimbleton was able to get inside the enclosure with him, and he was very friendly. In fact, it seems to fit the fairytale and what you see on screen. But, Gabriel is very rare.

WATCH: Nikki gets close to wolf dog Gabriel

"He's one in a thousand," Knight said. "What people want is a wolf that acts like a dog, and he's a rarity."

Most of the animals portraying wolves in Hollywood are just large dogs and not wolves at all. Real wolves and even hybrids have very different needs and behaviors.

That's why at Big Oak, they have acres of enclosures, custom ramps and lookouts, safety catches and lockouts, fencing that's more than 10 feet high and 2 feet deep. Some wolves can climb, and they love digging deep dens.

"They're designed to casually trot 60 to 80 miles a day, and people have them living in their houses," Knight told News4Jax.

That's why listings online where wolves are selling for thousands of dollars leave Knight crying wolf. He knows someone will pay the price now, and he could be footing the bill later if the animal is surrendered.

Knight personally pays to care for all of the rescued and surrendered animals, and he refuses to make money by putting them on display to the public.

"When you have 20 enclosures and close to 3 miles of linear fence and no revenue from exhibition like the other places have, it all falls on you," Knight said.

WATCH: Why wolf dogs are different than other pets

While it is legal to own a wolf-dog hybrid, owning a pure wolf is illegal or requires a special permit in Florida. When it comes to the difference between a wolf and a wolf dog, Knight gave News4Jax an analogy.

"When you look at an NFL team, the second string is still an NFL player. It's the same thing here. A wolf dog is still a wolf," he said.

WATCH: Why sanctuary struggles to provide for wolves it houses

Big Oak Wolf Sanctuary is in dire need of financial help to continue operating. A crowdfunding page has been started to accept donations and offer more details on the animals the facility cares for and what they require. You can find that page here.