Your eye is caught by the sleeping dog, a massive, black Great Dane. You begin to walk over to the large metal kennel and open the door. Instead of inviting the awakening dog out however, you crawl inside, closing the door behind you with a loud metallic clank. You get off of your legs after crawling the door, as the kennel is tall enough for you to stand up with only minor bend in your neck. The dog, whose collar identifies him as 'Wrex', stands as well, coming almost up to your shoulder. He smells fantastic, you think as you begin to pet him wildly, running your hands over his head and back.
As you rub you notice something growing between his legs. His red cock is leaving its sheath! Instinctively, you drop all of your clothes, not even noticing the increasing blonde body hair growing all over you. You get down on your elbows and knees, your ass in the air. As he begins to lick you, you feel your ears twitch as they move to the top of your head, and your newly forming tail wag as it sprouts from your spine. You watch, over come with pure pleasure, as your hands turn to paws, and your legs shift to a more dog like state.
Suddenly, with a satisfying slurp, your cock and balls recede into your body, leaving you with a wet bitch-pussy. Finally Wrex mounts you, sliding his massive red cock into your virgin vagina. Your long pink tongue rolls out of your muzzle, as you moan in pure ecstasy, the last human sound your body makes. The Dane pounds away at your pussy, until he finally knots himself, and cums deep into your womb. Your mind begs for his pups. The feeling of his cum being lodged into your body makes you cum, as you stay like that locked, for hours until Wrex's cock finally deflates and he goes back to sleep. You curl up next to the giant, only a mere fraction of his size. Like a good bitch you don't like yourself, letting his cum run into your golden fur. Finally a pretty pink collar forms around your retriever neck, simply with the word 'Bitch' printed on it.