Kitty, Catty, Cater cornered or something else?

Never heard of any of those terms. I’d understand “diagonally opposite”, though.

Seconded. I grew up in suburban Cleveland, Ohio.

Kitty-corner, no ‘ed’ here. Oregon/California, fwiw. I’ve heard catty-corner, but never cater-corner, or anything with an ed at the end. Also, only ever heard it used for buildings.

Catty-Corner, no -ed, meaning primarily at the opposite corner of an intersection or sometimes diagonally in general.

Kitty-corner.
Ironically, I mostly use it as follows: “You know the petshop cats? No? Well, there’s this pet supply store kitty-corner from the school- no pun intended…”

(Is ‘ironically’ the right word here? Grammar Nazis, feel free to correct me).