So we all know the Potters had a cat, right?
All we have per descriptions of this cat is that 1. It was enough of a Potter to make the list when they went into hiding and 2. Harry scared it with his new broom he got from Sirius.
There is further no mention of said cat.
On the other hand, don’t we know another, really old, beaten down, ugly, sad, sad cat?
A cat that befriended Sirius Black and seemed to KNOW Peter Pettigrew’s smell, hold a grudge against him, even?
Part-kneazle, so it has a remarkable ability for finding things that are shiny and that it has a connection to, like, say, a family member.
A cat that knows it’s way around Hogwarts, around the Whomping Willow, almost like it had been there before with another owner.
A cat that absolutely REFUSED to let Hermione leave that shop without him after seeing a certain rat, was CRAZED, almost.
We have no mention of this cat/kneazle’s age, except that it had been in the shop for a while and no one had wanted it. Magical creatures live a long time. Cats live a long time. It’s within reason that this cat could be 30, even 40 years old.
It makes too much sense.
The Potter cat is Crookshanks.
This is by far one of my favorite HP headcanon and no one can convince me that this isn’t real.