One time I was trying to remember this phrase and I said it as “Buffalo buffalo buffalo Buffalo buffalo Buffalo buffalo buffalo.” It’s still grammatical, but the sentence has been reworded and no longer matches the popular expression. Luckily, nobody heard me capitalize it incorrectly.

There are others, i.e.,

Cheese cheese cheese Cheese cheese cheese Cheese.

I think you forgot this

https://wikipedia.org/wiki/Buffalo_buffalo_Buffalo_buffalo_buffalo_buffalo_Buffalo_buffalo

NVM, you linked it, it just was showing up as a black thumbnail for me

She said that that that that that boy used was wrong.

Okay, I couldn’t find the source. It maybe in the list