The character also crossed over into prose last year, with The Unbeatable Squirrel Girl: Squirrel Meets World, a YA novel by the husband and wife team of Shannon and Dean Hale that was successful enough that it spawned a sequel: The Unbeatable Squirrel Girl: 2 Fuzzy, 2 Furious, which was released this month.

The novels — which recast the college-age Doreen of the comics as a 13-year-old trying to get used to her new school, new town and new identity as a wannabe superhero — capture the comedy, optimism and heart that made the character such a success in comics, while adding in additional heroes from the Marvel Universe via helpful (and sometimes, the very opposite of helpful) text message exchanges. Heat Vision talked to the writers about translating characters into new mediums, the origins of squirrel names and why a 14-year-old with a bushy tail and a lot of optimism is just like Wolverine.

As someone who loved the first Unbeatable Squirrel Girl novel, I’m excited that it led to this follow-up. I’m curious: Was a second book always on the cards, at least in your minds??

Shannon Hale: Thank you! When we were writing the first, we weren’t sure if we would be lucky enough to write a second, so we wanted the first to stand alone but also leave room for more possible adventures.

Dean Hale: I’m convinced I’m dreaming, because what actual real humans get to write Squirrel Girl once, let alone twice?

The novels manage to take the very particular tone of the Squirrel Girl comic book series and translate — and expand — it into prose. What Ryan North and Erica Henderson do isn’t easy, and I’m impressed by how seamlessly you’ve managed to work that into the books. What was your method for writing the character??

Shannon: We asked ourselves, what would the Doreen Green in the awesome comics have been like in middle school? We’ve written books for lots of different age groups — 5-8 year olds, 10-14 year olds, 12 and up, adults, etc. — but this felt like the perfect place to explore what it would mean to be Squirrel Girl. Where better than middle school to have a 5-foot squirrel tail you have to hide in the seat of your pants?

Dean: Also constantly reading and re-reading the comics. We also have a vial (small) of Ryan’s blood, which helps. For inspiration.

Who is the quintessential Doreen Green to you? The books obviously have a message of self-belief and self-empowerment, but there’s something winningly fallible and charming about how Doreen gets there that doesn’t betray the optimism of the comic book. Who is your Doreen?

Shannon: I love Doreen’s optimism. She is unbeatable in large part because she believes she is. But she is also human. In the first book, we got to show her first grapple with this Squirrel Girl secret identity and come to embrace it. In the second book, being Squirrel Girl is going great! But being Doreen Green is more challenging.

Dean: Her world view and emotional resilience are so amazing to me. It’s like she’s an existential Wolverine, healing any wounds that pervasive environmental nihilism might inflict. Was that too nerdy? Probably too nerdy.

Shannon: There is no such thing as too nerdy.

There are two things that really stick out in both books for me. The first is the text relationships Doreen has with other Marvel characters. Where did that idea come from, and how do you choose which characters she’s talking to?

Shannon: In the comics, Ryan and Erica start each issue with a hilarious page of Twitter interactions between the characters. We wanted to keep the spirit of that, and when dealing with middle schoolers, that means texting. So. Much. Texting. We basically just chose the heroes we thought would be fun to write. How would a conversation between Winter Soldier and Squirrel Girl go? Or Rocket? Or Iron Man? We had to know!

Dean:There are lots of conversations that never make it into the books because we just can’t help writing them. It’s too fun.?

Secondly, I have to ask: The lists of Squirrel names. Where did that come from, and how did it become a thing?

Shannon: I’m going to take full credit because it was my idea, even if Dean is the one who actually wrote those parts.

Dean: I have a constant stream of nonsense running through my head at all times, so it was nice to get some of that out. I’m also a big fan of John Hodgman’s enormous lists of Hobos and Mole People in his books, so getting to do anything even remotely similar to that was a joy.

Shannon: In the second book, about twenty-five of the names were squirrelified names of real people.

One of the things that I enjoy so much about the books is that they themselves are very much what Doreen is as a character: inclusive and inviting. Sure, they’re theoretically books for younger readers, but I’m a [mumbles age] not exactly younger reader, and I find them really enjoyable. What has the feedback been from people from the books so far??

Shannon: Well, Dean and I are [mumbles ages] and we adore them, so you’re in great company! I think “all ages” is a tough thing to achieve, but the Squirrel Girl comics really do achieve it. We hear from readers of these books who are old, young, and middle, both long time Marvel fans and newbies, and anyone in between. Not every character can do that, but Squirrel Girl can.

Dean: She is unbeatable, after all.

The Unbeatable Squirrel Girl: 2 Fuzzy, 2 Furious is currently available.