I cut my cat's eye out in a rage after a night of drinking.
I hung the cat, even though I knew it did nothing wrong, I knew that it had loved me. I felt massive guilt.
When my house burned down in an accident, the only thing left was a wall with the outline of a cat in the ash.
I found a nearly identical cat in the tavern the next day, and decided to take it home.
When I tried to strike down the cat with my axe, my wife tried to defend the beast, so I killed her and hid her corpse in the wall. Upon police inspection of my house, the horrid cat revealed my secret, and I was caught.