Mason Thames may be leading the new How to Train Your Dragon movie — but he’s been a fan since day one.

“Those films defined my childhood,” says the 17-year-old actor speaking with People, as he reflects on the significance of his new role as Hiccup in the live-action version of the cherished animated series. “Being part of this universe feels unbelievable to me.”

Thames, who gained fame from his standout role in The Black Phone, confesses he was captivated right from his initial viewing of the 2010 DreamWorks original. “As a child watching the first movie, I felt such wonder and enchantment. Everything about it was amazing, especially Toothless, who’s just adorable.”

For Thames, the heart of the series wasn’t solely the dragons — it was Hiccup himself. “Growing up, Hiccup was my hero. I saw so much of myself in him,” he explains. “My journey into acting mirrored Hiccup’s quest. All he wanted was to be a Viking but was often underestimated and sidelined in his village. When Hiccup embraced his uniqueness, that’s when he truly became himself. I found that very relatable.”

Landing the role wasn’t just a big deal — it was a full-circle moment. “That was one of the best moments of my life,” Thames recalls of the casting call from director Dean DeBlois, who also helmed the animated trilogy. After a London chemistry read, weeks passed with no word — until he got a surprise call.

“Actually, we only have one question,” DeBlois said. “Would you like to play Hiccup in our movie?”

Thames’ reaction? “I stood up. I jumped out of my chair and broke my light,” he says with a laugh. “That was a very special moment. My family, they were really proud of it.”

Taking over the role once voiced by Jay Baruchel was no small task. “They’re very big shoes to fill,” Thames says. “Hiccup — that character is my childhood. I really wanted to do the fans right. Also for myself, because I’m a fan.”

That passion helped ease his nerves. “When you care about movies so much and you hear that they’re going to be making it in a live-action format, you get kind of nervous that it’s not going to be the same, that it’s going to be soulless,” he admits. “That’s something I was worried about until I met with Dean… You should see the love he has for these characters and this world and this movie. I think it really shows in the final product.”

While the live-action reboot doesn’t aim to replace the original trilogy — which earned Oscar nods for all three of its films — Thames sees it as a celebration.

“The original movie is, in my opinion, a masterpiece,” he says. “It wasn’t a thing of what can we change or make better than the originals. It was how can we expand upon this world and expand these characters. Bringing it to a new generation in a live-action format was a lot of fun.”

And for a lifelong fan-turned-star, it couldn’t be more personal. “This film, to me, feels like a love letter to the original.”

How to Train Your Dragon, which also stars Gerard Butler, Nico Parker, and Nick Frost, is now playing in theaters.