Harry Potter theories are fun to create, share, and consider. But you don't have to believe all of them — some are just obviously wrong. Such as a fan theory recently highlighted on Quora that supposes that Crookshanks, Hermione's supremely ugly cat, was once owned by Harry's parents.
"There is a popular theory that Crookshanks is actually Lily Potter's cat," the Quora post begins. "In The Deathly Hallows, when the trio are in Grimmauld Place, Harry reads a letter hand-written by Lily. In the letter, she mentions that they had a cat and that Harry almost ran over it with his toy broomstick. Harry even wonders if it survived the attack by Voldemort and if it was alive. In Prisoner of Azkaban, the owner at Magical Menagerie from where Hermione buys Crookshanks tell her that she had had Crookshanks for 'quite some time' and that nobody ever wanted him. This could correspond to our earlier timeline where the cat disappeared after Voldemort's attack on the Potters' residence. Soon after Crookshanks is bought by Hermione, he quickly recognizes Scabbers and the shaggy dog as Peter and Sirius respectively. The fan theory goes that Crookshanks recognized them both because they would have frequently visited Lily and James when he was with them."
First off, let's attack the idea that Crookshanks "recognizes" Sirius or Peter. Really, the squashed-face marvel "recognized" a dog and rat, things almost all cats will chase regardless of any potential human identities. Most importantly, Crookshanks is a distinct-looking cat who lives in a school with many teachers who either taught or were besties with the late Potters. After all, since every adult who happened upon Harry felt compelled to tell him how much he looked like his deceased parents, wouldn't one have been like, "And what a coincidence, that misshapen creature always hanging around your friends was actually once your family pet"?
Still, fans want J.K. Rowling to confirm or deny this obviously false theory. Hopefully she replies to their eager tweets and debunks this for good.