The design I use here for the Ninjanomicon was originally created by tumblr user notnights near the beginning of this year. Her design has swept the fandom and become incredibly popular to the point of some Titmouse members drawing fanart! A big honor, to be sure. The design I use most commonly is my own “casual” outfit design because drawing all those swirlies and the cloak every time isn’t really my thing (and also cuz I love making up simple outfits for characters).
This ask blog is based off of my own headcanons which may or may not match up with notnights’ own ideas for the character (for instance, she sees the Nomicon as mute while I prefer him to voice his snark). We both view him as genderless, but I consider him to lean more towards being male, mentally, due to the circumstances of the time when the book would have been created. Thus, me constantly refering to a book as “him.” Of course, the Nomicon’s outer appearance changes depending on the expectations of the ninja
HEADCANON ALERT, so that all really depends.
So, in short, you could call the Human!Nomicon that you see here a marriage between notnights’ and my ideas for the character. Notnights intended Nomi as a blank slate to be filled, so don’t be afraid to interpret him as you like as well!