In a sudden fit of desperation, you look around the room rapidly for any sign of a mirror or other reflective surface. The best you can manage in this room is the glass door that allowed you access to this place. It's hard to see your reflection in the transparent glass, but it is there, and upon catching even the faintest sight of yourself, you let out a sudden roar of shock.
It's as though a lion's head were placed onto your human body.
One instinct is to run far, far away from your reflection, but that would solve nothing. You take a deep breath and take off your shirt leaving yourself bare-chested. The fur only seems to go down your neck; where the mane ends, the fur lends down in layers to match your bare skin.
For a moment, you suspect that nothing else will change other than your head. This idea quickly fades as a pressure builds in the rear of your pants. Without hesitating, you strip down naked where you stand; the pressure was coming from a hard growth near the base of your spine. It continues to grow longer but remains slender, and a similar tawny fur begins to cover it. A fluffy tuft, brown like your new mane, forms at the end of the tail as if to indicate it's done growing.
"Crap, is my whole body going to change?" you say out loud. Or try to. It only comes out as another roar: your voice changed with your head. You realize you may not have much time before your whole body is changed. Is there a cure? Will you look for one? Or will you embrace the growing beastial nature in your mind?