Buddy...This 'pet' is a lost soul. It assumes the form of your most beloved pet during a time of crisis. When your spirits are at the lowest, Buddy may come to your door. If you invite it in, it will spend time with you, reassuring you with familiar voices that you just can't seem to name. For a month, it will be there, keeping you company, steadfastly loyal, obedient beyond explanation. Buddy will understand you and do anything you ask to help you feel better...
But if you panic and shut the door for this apparition, it never leaves. Buddy will haunt the outside of your home, and throughout your days, you'll hear whispers about everyone you ever failed, abandoned or let down. The whispers will be those of your friends and family, their voices disgusted and hateful. They will drive you mad, never stopping, never giving you peace until you either take your life... Or let Buddy in... Except since you refused Buddy's help... All Buddy will give you now is death.
Oh of course. Maimed, neglected, rotted, exposed bones and torn fur, blood smeared all over her coat. She meets you at the door with a smile as toothy as a shark's, and as sharp as a razor. She doesn't rush, no... You have nowhere to go. She pads her way in, smiling up at you, her eyes shivering in their sockets while she stares right through your own, a stare so singular in purpose that you CAN FEEL her searching your soul. She trots in, slowly, predatory with that damned, vicious smile, her cheeks torn to expose every last tooth... She doesn't go for the throat like most animals... She goes for your heart.
You can hear her whispers in your mind... Echoing from all directions... "Too late... Too late... You abandoned me for the last time..."