Interview: Inside Nat Geo’s "Underdogs" with Showrunner Dan Rees

From mucus-coated grubs to glow-in-the-dark caves and unconventional courtship rituals, National Geographic’s Underdogs is a nature series like no other. Executive produced by Ryan Reynolds and brought to life by the Emmy and BAFTA Award-winning team at Wildstar Films, the five-part series spotlights the unsung heroes of the animal kingdom with irreverent humor and scientific rigor. Ahead of the premiere, I sat down with Executive Producer and Showrunner Dan Rees to discuss the show’s unique tone, the challenges of filming creatures who rarely take center stage, and how the team blended factual storytelling with unexpected comedy.

Alex: Congratulations on the launch of Underdogs, Dan. I’m curious to know—how did you balance the scientific integrity of the series with the irreverent tone brought by Ryan Reynolds’s narration?

Dan Rees: Well yeah, I mean, it was constant in the back of our minds. We wanted this series to amuse but also amaze in equal measure. I think it's down to story selection. At the end of the day, when we chose our characters, we were looking for animals who we could establish as underdogs. They needed to be gross, or weird, or downtrodden, or overlooked—and also doing behavior that was kind of "underdogy." It might be bizarre, or just really surprising.

Within that, there was always potential for comedy. But we also wanted great factual stories. That all comes together with relatability. We worked really hard to establish the character of these animals—what is their personality? How can we make them relatable so people understand their motivations?

Grounding it in fact is key. Truth is often stranger than fiction, and once you find the weird stories, the comedy takes care of itself—especially when you bring in Ryan's tone. The guy could read the phone book and make it funny.

But a key thing for us was: the stories had to be funny before Ryan even came in and said a word. We’re choosing unusual characters with comic potential, placing them in funny situations, shooting it beautifully, editing it beautifully, adding the right music—whether it’s a commercial track or Harry Gregson-Williams’s amazing score. So it’s all both funny and factual before Ryan even starts narrating.

Alex: Speaking of the music—you mentioned Harry Gregson-Williams, and Green Day is also contributing to the series. How did that all come together?

Dan: Harry was someone my colleagues Mark Linfield and Melissa Berwick had worked with on a DisneyNature film. So they already knew his amazing talent. This series was a tough ask because we needed someone who had written for animals before—which is a particular skill. You don’t have human dialogue or emotion to bounce off. Not everyone can do that.

We also needed someone who could do comedy and had a wide range of styles. And really, who else could do this but Harry? If you look at his filmography—from Shrek to The Martian to Gladiator—he’s just got such a broad skill set. He was amazing to work with.

As for Green Day, that came through the team at Maximum Effort. I think Ryan knows them personally. When we were talking about getting a song for the series, they said straight away, “Green Day." They’d worked with them on Deadpool. We reached out, and they were just on board immediately. They saw our sizzle reel and early cuts, and they loved it. They came up with the song so quickly. It was amazing. I'd love to catch up with Billie Joe and ask how that track came about. It really sets the tone for the whole series.

And of course, we’ve also got a great range of commercial music throughout the series, which really helps us establish humor and personality.

Alex: There are a lot of great needle drops throughout the series. Now, each episode tackles a different theme, and I’m curious—was there a topic that particularly surprised you or changed the way you viewed these animals?

Dan: Pretty much all of them! I’ve been making wildlife films for well over 20 years, and what was amazing with this series was that we were looking for animals who don’t usually get to be the stars. That means you’re discovering all these new characters and behaviors. I was constantly surprised by the research my amazing team was bringing me.

We deliberately wanted to be unpredictable. The format is to have no format. We wanted viewers to always be wondering, “What’s he going to do next?" You never quite know what Ryan’s going to say. He’s like the eccentric architect of the series—this big kid who got to make a nature show with crazy ideas about how to do it.

Each episode has a distinct identity. In terms of specific stories—this might sound childish—but I’m a big fan of the pearlfish. I don’t know if you saw that one, but it’s a tiny, transparent fish that, when threatened, hides up the—pardon my French—anus of a sea cucumber.

Sea cucumbers are normally highly toxic, but the fish is coated in mucus that allows it to slide in and prevents it from being poisoned. When a producer first brought me the story, I was skeptical. I didn’t doubt it was true, but I questioned if we’d be able to film it. It’s a tiny fish on a coral reef in Polynesia! But the team convinced me, and they absolutely smashed it. It’s such a good story—it ended up being the opening scene of one of the episodes.

Alex: My next question was going to be about challenging scenes to film. Was that the most difficult, or were there others?

Dan: There were lots of tricky ones, but the one that springs to mind is the glowworm cave—or the “snotworms," as we ended up calling them.

This was filmed in a cave in New Zealand no one had ever filmed in before. The crew had to climb down a narrow chasm to a tiny cave entrance—and they had to do it at night because that's when the glowworms glow. They were waist-deep in water, carrying all this expensive gear.

Even though to the naked eye the cave is quite bright, the cameras still need to be super sensitive. They had to set up all this fiddly macro gear without any white light—because the moment you use it, the worms stop glowing. We used tiny rails and tracks for macro shots, and for the predation behavior, we couldn’t use white light either.

So the team used blue lights, which are the same wavelength as the light the worms produce. That way, the worms didn’t react to it—and we could capture the predation behavior naturally. It took a ton of preparation and technical effort to get that scene.

Alex: That’s awesome. For my last question: Underdogs is launching globally on Nat Geo, Hulu, and Disney+. What kind of audience are you hoping to reach, and what do you hope they take away?

Dan: We’d love to reach people who don’t normally watch nature shows. Ryan brings a new voice to the genre, and we hope folks who’ve thought wildlife shows aren’t for them will give this a try.

We’re aiming for a broad audience—older children, younger adults, older adults—across the board. And what do we hope they take away? That every animal has a great story to tell. No matter how insignificant, weird, or gross, there are amazing stories everywhere in nature. That would be a wonderful takeaway.

Alex: I think they will. And congratulations again. Thank you very much for your time.

With its offbeat tone, unexpected stars, and visually striking footage, Underdogs delivers a fresh and wildly entertaining take on the natural world. As Dan Rees explains, the show’s mission is not just to surprise and amuse, but to invite viewers to appreciate the overlooked creatures who play vital roles in our ecosystems. Whether it’s a glowworm’s dazzling display or a pearlfish’s unusual hiding spot, Underdogs proves that nature’s strangest stories are often its most unforgettable.

Underdogs premieres Sunday, June 15th at 9/8c on National Geographic and ABC, and will be available to stream the following day on Disney+ and Hulu.