How many things in fiction have been referred to simply as “It”? (I’ll allow slight modifiers such as Cousin It from the Addams Family).
The city-controlling brain in A Wrinkle in Time.
Nitpick: His name was “Itt.”
Stephen King’s book of the same name.
It! (1967)
https://dailydead.com/wp-content/uploads/2016/05/It.jpg
Although not shown, there is a scientific mishap near the beginning of From Beyond (1986) whose results are cogently summarized by a witness (Jeffrey Combs): “It…ate him.”
Under “slight modifiers”, we might also include “the Great Whatsit” from Kiss Me Deadly (1955).
A bit of a stretch perhaps: It Came From Outer Space.
It is the name of the last song on Genesis’ double album The Lamb Lies Down on Broadway. I think the lyrics and title of a song count as fiction, yes?
Shhhh…it’s around the corner. (Well, it was funny when I was in 2nd grade)
‘A Child called It’ by David Pelzer.
Information technology.
Clara Bow was the “It Girl”.
My Wife.
In addition to King’s novel, there’s also a short story by Theodore Sturgeon called “It!” First published in Unknown in 1940. The “It” of the title is a plant monster that’s formed around a human skeleton.
In the same vein, It Conquered The World. That’s “It”.
Theodore Sturgeon’s short story from 1940. Creeped me out when I read it in an Alfred Hitchcock collection as a kid.
Tag! Now you’re It!
Ok, now how many Things are there? The Thing from the Fantastic Four, Thing from The Addams Family, The Thing from another World…
1970s’ joke:
Q. What do monsters eat?
A. Things.
Q. What do monsters drink?
A. Coke. Because things go better with Coke.
If we’re expanding this to “Things”, you gotta start with The Thing (the shapeshifting one in Antarctica) in its various incarnations. Also Man-Thing and Swamp-Thing for your basic shambling horrors.
And then maybe we can move on to Them, including giant ants and the kids from “Good Omens”.