Disclaimer: not mine

Cats.

John absolutely loathed cats. The way they constantly preened and made note of their own self-importance. How they constantly demanded attention, and how they were perpetually lazy until something new caught their eye. He hated how they couldn't get along with anything either. Birds, they'd eat. Dogs, they'd scratch, and for goodness sake humans were only tolerated because they gave attention freely.

Oh God.

The website. Attention…

A Case. Something new…

Birds. Criminals…

Dogs. The police force…

Humans. Lestrade, Mycroft, John…

Oh no no no no no no no no no no…

John had a cat.