Think about it, how many Names One Should Not Even Think Of do you know?
Honestly, not that many. I know some basic lovecraft stuff: Cthulhu, Azathoth, Nyarlhotep(I know I'm not spelling that right), The King in Yellow but I'm pretty sure he's dead so that's probably safe, I think old man Henderson counts. I know that hungry star of malice is out there but I don't remember his name. Night Gaunts, Shoggoths, Old Ones, Dagon. Do you think it's safe to think about lovecraft locations? Like would I get Dagon's attention if I start talking about a little place Innsmouth without ever mentioning him specifically?
The Endless go without saying considering how much they've featured but I've got some other DC trivia around. Like the Hell branch of the Bloods and the Crips, and Trigon, unrelated. I think. If the hate star from Lovecraft counts than Sol and Rao sort of counts. Barbatos is a thing everyone should avoid. The Blackest Night and the fuckers connected to it are bouncing around in my head somewhere, just not right now. Christianity is a thing in DC so I guess I should be wary of named Angels as well, Lucifer ain't gonna give a shit, I live on the East Coast. Krona might get his attention, might get the Guardians attention. Could maybe include the Light Creatures: The Will Whale, the Greed Snake, the Predator Predator, etc. Mr Mxy is pretty explicit when it comes to not saying his name, same goes for Batmite and the Great Gazoo and any character with knowledge of the fourth wall: so anyone with Pool in their name, most loony tune characters, Beetlejuice or any variation of it, Garfield is to never be given focus, Gorefield must never be.
Marvel is connected to DC so all those fuckers are out as well: Galactus, the Inheritors, Dormamu, Agamatto and his rival that I don't remember right now, that Starfish alien in Marvel vs Capcom, Cytorrak, Lady Death, Stan Lee/Jack Kirby/The One Above All, though he probably wouldn't mind, the Below All, he would. Oh, DC has that knock off Cthulhu that Solomon Grundy helped stop. Greater Darkseid counts though I doubt he'd do anything, me being so far below him. Regular Darkseid might count and is more likely to act.
The Tulpas probably count but aren't likely to do anything out of character. So: Santa and Mrs. Claus, Easter Bunny, Jack Frost, Tooth fairy, Boogieman, (we already know who the sand man is... Does the Boogie Man have another Identity?), Man in the Moon, Uncle Sam, the Queen of England(I don't know what her deal in DC is outside of something to do with Devils but I fully believe she has one somewhere), Elvis Presley(The other person I believe has a Tulpa running around,).
Truth is pretty passive, pretty sure the anime versions of Lovecraft beings are the same existence as the classics, Kyubey probably counts. Hmm
I think that's it for now.