For those Pokémon fans who wonder just how Pikachu conducts electricity or Bulbasaur sprouts, artist Christopher Stoll has (unofficial) answers for you. The biologist and illustrator is working on volume two of his guide to Pokémon anatomy, also known as PokéNatomy. His new illustrations reveal fresh insights about characters not included in volume one.

For instance, Smeargle’s anal glands are at the tip of its tail, implying those secretions are used as paint. Girafarig’s two heads share a stomach and digestive system. And Wobbuffet’s skull is actually in its tail, leaving only muscles inside its head.

We learned about the new round of artwork thanks to GameSpot. They referred to it as nightmare fuel but I think this content is super cool. And so educational! Stoll says his drawings are used in hundreds of classrooms to help teach anatomy. He raised nearly $35,000 on Kickstarter for the first book, which can be purchased on Amazon. No specific news about the sequel yet, other than the new artwork Stoll released on social media

Looks like other characters coming to PokéNatomy Volume II include Steelix, Tyrano, Donphan, Espeon, Bellossom, and Togepi. There’s nearly 1,000 total, enough to fill many more volumes. Here’s hoping Stoll keeps up the good work and makes the comprehensive set.

There’s so much potential for educational Poké content. Another artist, RJ Palmer, draws realistic Pokémon and even recently created new Pokémon based on evolution. There’s also Squirdle, a Pokémon Wordle variant. If you’re really looking for disturbing, there’s also videos on how to cook Pokémon.

Close ups of four Pokémon with half being inner anatomy
Christopher Stoll

Now that we know how Poké Balls work, it may be hard not to consider these anatomical insights next time you’re playing Pokémon GO.

Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.