Harry Potter and the Philosopher's Stone was released in the United Kingdom exactly 20 years ago today, which is sort of scary. Didn't I just read Harry Potter for the first time, soundtracked, probably, by the Spice Girls' magnificent Spiceworld album, or someone's Tamagotchi announcing its death with a chirp? The speed with which the Earth turns is unsettling, indeed, and to celebrate Harry Potter's milestone, the New York Academy of Medicine in East Harlem has dug up some even older books—they're releasing a digital archive of literature dating as far back as the 15th century that focuses on some of the creatures, plants, and other magical entities featured in the series. If you've ever wondered what a real merperson looks like, now's your chance.

The collection, dubbed "How to Pass Your O.W.L.s at Hogwarts: A Prep Course," is meticulously put together by library curator and Harry Potter superfan Anne Garner, and sources from a few of the 160-year-old historical library's extensive collection of medical texts. Garner has separated the texts by class, so if you prefer to spend some time with Hagrid and Buckbeak, you can peruse the "Care of Magical Creatures" collection, complete with dragons and the aforementioned merpeople from Italian naturalist Ulisse Aldrovandi's 16th century animal encyclopedias, unicorns from Swiss naturalist Conrad Gessner's 16th century manifesto Historia Animalium, and a 17th century illustration of Athanasius Kircher's three-headed dog (Fluffy!)

Swing by Professor Sprout's greenhouse, and you'll be blessed with an adorable drawing of a pair of mandrakes from the 15th century Hortus Sanitatis, while Potions class with Snape includes a photo of a real life bezoar—which, it turns out, does not work as an antidote to most poisons, much to the chagrin of one 16th century cook who had the misfortune of serving as a human experiment.

And if you can find a teacher to survive helming Defense Against the Dark Arts for long enough, you'll be blessed with humanist Konrad Lykosthenes' 16th century Phoenix and, my personal favorite, Aldrovandi's basilisk, which looks more like a grumpy armadillo/bird hybrid than a big scary snake that haunts the Chamber of Secrets, but no matter.

The collection includes some 17th and 18th century texts on alchemy, as well—including one with a reference to Nicolas Flamel, who you might remember from the first Harry Potter book. Flamel was a famous bookseller in France in the 14th century, and though he didn't really invent the Philosopher's Stone, he has (probably erroneously) been remembered posthumously as a successful alchemist.

There's also a very cool-looking little book from 1593 that details witch-hunting, if you're in the market for some tips.

The collection is a must-see for Harry Potter fans and book lovers alike, but there are two pieces of bad news. First, there are no Charms lessons to be had here—though there might be a spell or two hidden in the medical library's vast archives, Garner hasn't yet come across any incantations that would make teacups dance or feathers levitate. The other thing is that for now, the texts are only accessible via the Academy of Medicine's digital archive (which you can access here), though Garner says the library will offer tours soon if you want to see the books IRL. For now, click through the above photos from a recent tour given to Gothamist.