Today, there is plenty of young adult literature aimed at trans kids, or starring trans characters. Ok, maybe not plenty, but there’s some: George by Alex Gino, or Luna by Julie Ann Peters, or I Am J by Cris Beam. I think some of these books are controversial, maybe for being written by cis people, or reinforcing normative tropes, or whatever: I have a friend, a literature professor with a young trans daughter, who has studied these books, and could explain this more at length. Still, these texts exist.

That’s not what I remember about being a tween in the 1990s. By high school, I had found What Happened to Lani Garver, in which the trans kid dies and the cis friend learns a valuable lesson. When I grew up, I discovered Orlando, Virginia Woolf’s gender-swapping satire of Britain’s patriarchal literary canon, which got me into grad school. But as a kid, like, a little weirdo kid, there was only Animorphs.

I discovered Animorphs in the fourth grade, the first time that I became a boy. I would borrow my neighbor’s baggy jeans and surf-shop t-shirts, smuggle them into school in the bottom of my backpack, and sneak into the cramped stall of the girl’s bathroom to change. I was probably wearing these clothes when I caught sight of these now-iconic David B. Mattingly covers at a Scholastic Book Fair, an oasis amongst the displays of Dear America books for girls and My Name Is America books for boys. On the front of these short trade paperbacks were images of transformation: over a series of five drawings, a pale boy’s arms might elongate and burst with feathers, or a girl’s smooth brown skin become the rubbery grey form of a dolphin.

I loved Animorphs for much longer than was socially appropriate, long after I decided that I would not enter middle school in boys’ clothes, my scraggly hair hidden under a baseball cap. This first detransition was frightening, and I did badly. In my retreat, I found an online community of other Animorphs devotees, other kids who were drawn to texts in which bodies change their forms painlessly, whose human bones can easily break and reassemble into those of wolves, or hawks, or rats. In the last few years, I’ve wondered who else from those message boards grew up to be a transsexual literary critic.

When I meet trans people for the first time, especially in mixed company, I’ll sometimes try out this line where I mention Animorphs offhand, as if I don’t take it seriously, as if I didn’t spend the majority of my first puberty wishing that I were turning into a bird or a tiger instead of into a young woman. More often than not, trans folks will say something to me like, “Oh my god, right? Tobias was totally trans!” Cisgender people will usually take this as their cue to get another drink.

They’re so right: Tobias was totally trans. Of the six main characters in the series—it was an era when having an ensemble cast of multicultural teens seemed to be a golden ticket for Scholastic—Tobias was the dreamboat orphan, the one whose eyes were most likely to be described as “sad” and hair as “tousled.” Of course, that was only in his human form. The catch with morphing was that you can only be an animal for two hours at a time. If you don’t demorph after that, you’re stuck forever in that body: in the alien language of the text, you become a nothlit. Tobias became a nothlit at the end of the first book. For fifty-three more installments, he had the mind of a human boy, and could even communicate with humans using a form of telepathy, but lived in the body of a hawk.

In the third book, Tobias attempted a red-tailed-hawk form of suicide, flying at speeding-bullet hawk-dive speed, first into a brick wall, then towards a glass skylight. Only the intervention of a few friends kept him from killing himself, ruining the body into which he found himself trapped. The books are for children, so the text doesn’t read, “Tobias was trapped in the wrong body and wanted to kill himself.” And at other points in the series, he seemed to relish the opportunity to fly away from his human troubles, his school bullies and abusive guardians. And still later, through a somewhat ham-handed plot device, he regains the ability to morph from hawk into another creature, including his own human body, for two-hour intervals. His relationship to his sense of bodily wrongness is complicated. Regardless, Tobias’s narration is full of longing and angst, waves of self-disgust each time he chokes down a rodent, grim musings on how long he’ll survive in a wild body that doesn’t match his mind.

This tonal darkness explains why Animorphs, more than other texts with transfigurative plot devices, captivated my generation of proto-trans readers. Plenty of Harry Potter fans, for example, might point out that Polyjuice Potion contains some dramatic possibilities for hypothetical trans Hogwarts attendees, or that metamorphmagi (who can change their appearance at will) might be inherently non-binary. But Animorphs isn’t set within an epic struggle of good versus evil; instead, the teenaged protagonists discover that they’re in a guerilla war, a battle in which their closest family members and confidants might turn out to be enemies.

On the reverse side of the book covers that had captivated me as pre-teen, boilerplate language reads:

We can’t tell you who we are. Or where we live. It’s too risky, and we’ve got to be careful. Really careful. So we don’t trust anyone. Because if they find us… well, we just won’t let them find us.

In other words, much of Animorphs is about living in stealth. The kids are fighting a war against parasites which infest the bodies of human hosts. One main character has a beloved older brother controlled by the enemy; another, a mother. In a cutting scene in the second book, a girl bursts into tears when it becomes clear that her parents, whose parasites are distracted by their part in the ongoing invasion, no longer love her.

These beloved relatives, now serving as body-snatched alien hosts, cannot be allowed to discover the teens’ secret powers. The Animorphs slip out of their childhood bedrooms to go change their bodies, fighting in secret against adult humans who sound, to the outside world, perfectly normal. They tell their parents they are at basketball practice or a sleepover, when really they are sneaking off to turn into elephants or gorillas, to fight for their lives. In Harry Potter, there are some trusted adults who get it, who know that there are bad guys out there. In Animorphs, no one can find out who you really are. The consequences are deadly.

The books are, in the end, not just adolescent fantasies of changing bodies, but about what it’s like to be holding an urgent secret, the possibility of familial love and social belonging stripped away by a silent war. For some characters, like boy-turned-hawk Tobias, that war is doubled, internalized within the sensation of being locked into an unfamiliar body. But even the non-nothlits must keep their transformative identities secret, live with the fact that being revealed as something not-quite-normal could result in violence. When my trans friends and I say to each other that we’re fans of Animorphs, what we mean is that we, too, know what it feels like to be “really careful,” to not “let them find us.”

–Cassius Adair is a writer living in Ann Arbor, MI. Find more of his work at cassiusadair.com