A werewolf

Pain shoots all through your body as you begin to grow rapidly. Your muscles grow and bulge, tearing apart your clothes in seconds as fur sprouts everywhere. Every sense is heightened until you feel a guttural howl rise up from your gut and burst out, ringing through your supposedly sound-proofed basement.

You land on all fours, panting from the strain but recovering rather quickly. Your claws gouge into the tile covered cement floor even as you feel a raw, animalistic power surge into every part of your being. The part of you still trying to come to grips with the change is slowly losing out to the part of you that knows you've never felt this good, this strong, this amazing in your entire life.

As you stand, you bang your head into the ceiling, growling somewhat but surprised that you seem to now be about 9 feet tall. Fur covers every inch of your body, and you seem to have grown a muzzle along with the claws, pointed ears, and tail. **** to hunch over like this, you quickly become aware that every part of you has now become oversized, your exposed crotch sporting a sheathe alone that was larger than most normal human men ever hoped for.

Climbing up the stairs is a bit of an endeavor, requiring you to duck and turn sideways to fit your large shoulders through the small passage, but you make it. The entire house looks small now. You briefly wonder if this change is temporary, permanent, or you might some day learn to control it, but you quickly find you don't care. If you can't return to your previous life, then whatever. Right now you have two very pressing needs that need to be addressed, though you can't quite decide in which order. Your stomach rumbles for food, and your quickly hardening cock demands attention.

You remember your girlfriend is coming over soon. You could get something to eat as you wait for her and hope she understands. But you wonder if you might hurt her, as your aggressiveness seems to have grown to match your body. Maybe going for a hunt to test out your new body would be best. Then again, that little vixen of a next door neighbor spent all day teasing you in that tiny bikini in her back yard...