That reminds me when I searched up something horrid (I don't remember what it was) then put in brackets after "chill fbi it's for a book" LMAO
But uh... for writing, probably the weirdest thing I've looked up was simply anatomy stuff for drawing (not any NSFW areas just like the human body in general and getting some... weird results), how certain injuries (from a car accident or falling from a cliff, for example) can cause certain, horribly painful side effects if not death... and also perhaps a few too many 'what does it feel like to fall from a great distance', 'what happens if you overdose on ____', etc.
I swear authors must be the bane of authority's existence sometimes, y'know? Be like
"uh hey boss some dude's looking up how to (INSERT A LOT OF HORRID THINGS HERE)?? that sounds bad we should look into it"
"leave it be, it's just another author"