A few miles from the tail end of Garden State Parkway South, in an upstairs corner of Victoria and Steve Zelenak's Cape May home, a rat dangles from a ceiling fan.

This is no ordinary rat -- he is Splinter, sensei and mentor to the Teenage Mutant Ninja Turtles. And he is not alone. The entire two-toed crew -- Raphael, Michelangelo, Donatello and Leonardo -- fill the space in the form of action figures, plush dolls and comic books. But that's not all -- the turtles' green, masked mugs are splashed across tubes of toothpaste, packs of bubblegum and boxes of gelatin dessert mix.

You see, Victoria and Steve's son, Jonathan, is the ultimate ninja turtles fanboy.

Yet this explosion of "turtle power" is all too organized to be the domain of a child. That's probably because Jonathan Zelenak is 31.

He calls the space The Sewer Den, in tribute to the wisecracking anthropomorphic turtles' subterranean lair. Zelenak, who does not live in Cape May, makes his home in New York and works as a freelance video editor and producer. He defines the turtle shrine, which he visits when he wants to escape the city and see his parents, as a "museum of memories," reinvigorated by various reboots of the original TV series and movies popular in the '80s and '90s.

The creator of this radical, tubular homage to everything "TMNT" says the mini-museum is as much a celebration of his own childhood as his favorite turtles. In the course of showing off his collection, he's networked with other kids of the '90s who share similar memories.

"A lot of us just like nostalgia," he says.

Once a fan, always a fan

Like any good superhero -- or team of mutant ninjas, for that matter -- Zelenak has his own "origin story."

He first picked up a ninja turtle action figure in 1988, when he was 5 years old. It was the beginning of a plastic green love affair. The "Teenage Mutant Ninja Turtles" animated series, which started as a miniseries, was by then a regular TV show. Zelenak, an only child, was enthralled by the notion of a band of pizza-craving, sewer-dwelling buddies who fought the bad guys.

The fascination with all things ninja turtle began when Jonathan was 5. He danced with Raphael at his 7th birthday party. (Courtesy Jonathan Zelenak)

When he was 7, Zelenak, then living in Whiting, went to see the live-action "Teenage Mutant Ninja Turtles" movie at the Ocean County Mall.

"I remember jumping down the steps, saying 'Cowabunga!'" he says.

"The first movie was like the nexus of my universe at the time."

By then, Zelenak had settled on the red-masked Raphael as his favorite ninja turtle.

"In the show he was very sarcastic and he had a little bit of a witty sense of humor, so I liked that," he says.

His mother, Victoria, currently principal and superintendent at Cape May City Elementary School, thought it wonderful that her son had taken an interest in the Renaissance painters.

"When I found out that they were turtles, I was a little disappointed," she says.

However when something else -- girls -- caught Jonathan's fancy, he ditched the turtle toys. Consequently, Zelenak calls his teen years a "dark" period of his fandom. All of that changed in 2003, with the debut of a new animated series.

"I saw one (episode), it hit me and it all kind of rushed back," he says. So while Zelenak, then in college, had moved to New York, when his parents relocated from Ocean County to Cape May in 2004, he began to unearth all of his ninja turtle toys from basement boxes.

They let Jonathan set up his memorabilia in a spare room, and The Sewer Den was born.

On the wall, pressed into frames, are ninja turtle T-shirts he used to wear to school. Hanging from the door is the ninja turtles jumpsuit he donned to dance with a life-size Raphael at his seventh birthday, and the ninja turtle pajamas that doubled as his Halloween costume. There's even a bunk bed, covered in ninja turtle sheets.

Zelenak opens the Technodrome, a playset he says is probably one of his more valuable toys -- it can go for hundreds on eBay. (Amy Kuperinsky | NJ Advance Media for NJ.com)

Jonathan's father, Steve, a civil engineer, still buys his son ninja turtle toys.

"He always wanted to keep the box that everything came in," he says. For his 30th birthday, Zelenak got a 40-inch sewer playset.

While it was his idea to pull the toys out of storage, Zelenak's girlfriend, Jessica Dudley, attributes the groundwork for much of the collection to his parents.

"They're very, very sweet and sentimental people," she says. When Dudley, who works in fundraising at a private Manhattan school, met Zelenak, he didn't wait long to tell her about his room of turtle treasures in New Jersey.

"I don't think I really understood what he meant," says Dudley, 28, who has been to the Sewer Den many times since. Zelenak recalls her first reaction: "She said it was 'intense.'" But Dudley quickly grasped the vibe -- all the fun of the original turtle crew etched in retail relics both playful and ridiculous.

"A lot of the heart of the Sewer Den is not taking itself too seriously," Zelenak says. Though he doesn't typically dress up in full turtle gear, he does sport a green blazer and ninja turtle bow tie at comic conventions, along with a turtle-green pair of Nikes that were a gift from Dudley.

Driven by nostaglia

The Sewer Den isn't exactly an attraction, except for children of Zelenak's friends who visit from time to time. But in 2011, Jonathan brought his turtle collection to a wider audience by starting TheSewerDen.com, a website where he showcases various items from the room and talks about all the iterations of the franchise.

"I actually made a lot of friends through it," Zelenak says.

Zelenak hasn't counted his collection, though the 9-by-12 room is (neatly) filled to capacity with what he calls "mutant merch." To compare, the Guinness World Record for the largest collection of Pokemon memorabilia is a whopping 14,410 items; there are similar records on the books for Smurfs, Winnie the Pooh, Star Wars, Harry Potter, Simpsons and Super Mario Bros. memorabilia.

Still, interest in the teenage mutant crew in particular has rebounded strongly amid a wave of '90s nostalgia. In 2007, there was a CGI "TMNT" film. The latest TV reboot debuted in 2012 on Nickelodeon. There's another movie -- a sequel to the 2014 "Teenage Mutant Ninja Turtles" live-action remake -- due next year.

Individual TMNT action figures from 1988 can net anywhere from $20 to $80 on eBay, and one whole set including the turtles' reporter friend April is listed for as much as $1,150. A playset Zelenak owns that features the Technodrome -- a spherical home to the villain Krang and the spiky-shouldered Shredder -- can bring as much as $500.

Not that he's selling.

"I haven't gotten rid of anything at this point," Zelenak says.

Jonathan, all grown up, with the revamped Teenage Mutant Ninja Turtles. (Courtesy Jonathan Zelenak)

"The collection is a time capsule that highlights many moments of my life, and that is worth more than a heap of cash."

He occasionally buys trinkets to add to the Sewer Den, and not all finds are pricey -- for example, he displays a pack of turtle-branded Crush sodas that promoted the 2014 movie. In July he took a kind of "turtle expedition" to Japan in search of TMNT gear. Still, there's a limit to how much he'll shell out (no pun!) for a toy.

He would love to have a certain Krang doll, but he's not keen to spend hundreds of dollars for it.

The turtles themselves were born in 1984, in a comic book series by Kevin Eastman and Peter Laird. At peak "turtlemania," circa 1991, a sequel to the original movie, "Teenage Mutant Ninja Turtles II: The Secret of the Ooze," made its debut. The film's celebrated theme song was Vanilla Ice's "Ninja Rap."

As an adult, Zelenak met the '90s rapper at a work event and asked to see his ninja turtle tattoo. He has a photo with Ice in the Sewer Den.

"We were just two dudes who loved 'TMNT' years ago and shared that bond," he says.

When it comes to the future of his turtle collection, Zelenak anticipates that he'll eventually move it out of his parents' house one day. If he has children of his own, he figures, he may have to share in the turtle wealth.

"It's going to be a weird conversation," he says. "It's fair game."

Amy Kuperinsky may be reached at akuperinsky@njadvancemedia.com. Follow her on Twitter @AmyKup. Find NJ.com Entertainment on Facebook.