"Kids are disappointed when I walk into a school," a smiling R.L. Stine admitted on the final afternoon of New York Comic Con. "They expect somebody scary, and then I walk in, some old guy."

It's true: Stine appears far too sweet for someone responsible for the nightmares of untold millions. Of course, for many kids and 20-somethings alike, the author is more than just "some old guy”; as the creator of “Goosebumps,” the sprawling series of horror-comedy novels, he’s a part of childhood.

Since 1992, the Ohio-born author has been terrifying and tickling the imagination of young readers with his stories. Now fans of all ages will come together in shared love for Stine's work when the "Goosebumps" movie opens Friday nationwide.

"I've seen it three times," Stine told SPINOFF, although the first two screenings featured stand-in music in place of Danny Elfman's score. "The Elfman music just changes the whole film. It's amazing what a score can do for the whole film. … It just adds so much tension and so much suspense. It just sort of holds the film together."

The author seems to be a genuine fan of the film director Rob Letterman ("Monsters vs Aliens") has created. He spoke about it with a mix of pride and appreciation, happy in the product and touched to have such interest in his work. He even enjoys Jack Black's portrayal of him, even if it’s not exactly true to life. "Jack Black is hilarious,” Stine said. “Jack Black is very mean in the beginning. When we were first talking, when I met him for the first time, he was looking at me trying to figure out what to do. And he said, 'I'm gonna be a sinister version of you. That's how I'm gonna play you.' Because I'm not too sinister."

Before Black nabbed the role, however, fans wanted Stine himself to take the part. "I went to my wife Jane, and I said, 'Ya know, Jane, a lot of people think I should play myself in the movie,'" he said, referring to a vocal contingent on social media. "And she said, 'You're too old to play yourself.' What a terrifying line is that, right? ‘Too old to play yourself’? And of course she was right, so I was delighted they picked Jack."

The film is a kind of meta-adaptation of the "Goosebumps" novels. Instead of translating any of Stine's stories directly, it centers on a fictionalized version of the author as he battles his own creations when his daughter's new friend accidentally unleashes them into reality. Almost every one of Stine's classic monster and villain creations is featured in some capacity, which leads to the question, What happens if the film's a success?

"What would they do for a sequel?" Stine pondered. "They used everything already!" A sequel has reportedly already entered production, but the writer isn't one to count chickens. "I would say if a lot of people come to the movie this weekend, there'll be a sequel. It's pretty much up to that."

Asked whether making a true adaptation of one of the "Goosebumps" books is a possibility, Stine recalled, "We did an hour-long version of 'The Haunted Mask.’ It was the first primetime 'Goosebumps' TV show, and it worked good. I don't know if that would make a feature. That's always been one of my favorites."

Talking about which of the "Goosebumps" tales he takes the most pride in, he also mentioned "Say Cheese and Die" and "The Cuckoo Clock of Doom." "And there's one that nobody knows about and no one likes called 'Brain Juice' that was done later, which is one of my real favorites," he added, sounding like a kid with a secret treasure.

Although "Goosebumps" is undoubtedly his most famous creation, Stine actually has enough series to fill an entire kids’ section at Barnes & Noble. There's "The Nightmare Room," which had its own Saturday morning TV show ("A very nice show," Stine noted); "Mostly Ghostly," which the author said was his take on the 1950's sitcom "Topper" for kids; and "Rotten School," a 16-volume comedy series. Most of the lines blend comedy and horror, which makes one wonder why he didn't just keep "Goosebumps" running uninterrupted.

"That's a long a story," Stine explained. "That's publishing stuff. That was hard. We did 62 'Goosebumps' books, and then there was some legal problems and things. There was an eight-year break until we started it up again." It was during that time that he launched "The Nightmare Room" and other projects.

Even before "Goosebumps," Stine was writing horror tales for younger readers. His "Fear Street" series was aimed at teenagers, and like "Goosebumps," is something he's returning to once again. "I'm killing off teenagers!" he said gleefully. "It's great!"

There's also been word of a "Fear Street" film, but again, Stine is reluctant to get his hopes up. "It's a rumor. I've sworn not to talk about it,” he said. “I hope to have some kind of 'Fear Street' announcement sometime soon. I hope to. I mean, a really big thing. But who knows! There's no contract or anything. It's a rumor." Told the announcement is already listed on his Wiki page, the author replied, "It is? But we haven't signed a contract!" He chuckled as he expressed amused befuddlement with Hollywood. "You couldn't do that in books. Announce a book before you had an agreement? Can you imagine?"

He does have a history in Hollywood, however -- at least on television. Credited as Bob Stine, he was the co-creator and head writer of the Nickelodeon program "Eureeka's Castle." Although it aired from 1989 to 1995, he still gets recognition for the show via social media. "I loved that show," he said, delighted instead of nostalgic. "That was my whole TV career. I wrote all the puppet episodes. … Those puppeteers, they were all trained by Jim Henson. They were wonderful people, and the puppets were great. It was a lovely show. It was 'Sesame Street' without teaching them anything." He looks back at those four years as "a great time," one he joked was ruined by a certain prehistoric character. "And then this big purple dinosaur came along and ruined everything. That horrible puppet! It was awful. We had all this sophisticated stuff, we had a two-level set, we had everything. And this guy in a purple suit …" He trailed off, laughing.

But after four years of entertaining kids on television, he found his calling in scaring them silly in literature. Still, the books weren't as terrifying as some parents might have wanted to believe. Stine said letters from concerned parents were common in the beginning, but the stories soon found their footing. "Once 'Goosebumps' was around for a long time, people knew what it was and they knew it didn't go too far and it wasn't really upsetting. But in the very beginning, no one had ever done a horror series for 7- to 12-year-olds! And the covers were a lot scarier in a lot of cases than the book."

Twenty-three years later, and "Goosebumps" is primed for another major resurgence. The film is earning solid reviews (sitting at an 80 percent on Rotten Tomatoes as of this writing), and Stine has more books coming under the "Goosebumps Most Wanted" banner. But even after all this time, the author isn't shocked he's back with the kinds of tales he's famous for.

"That's what I'm really good at, the 7- to-12-year-old audience and that kind of combination of scary and funny," he said knowingly. "It's what I like the best."