a Percheron colt." She gestures, and before you can move, a strange warmth flows over you. The sensation is so unexpected and pleasant that you don't notice the changes. At first. Then you realize that the woman and the mare are getting bigger. So are the trees. And your clothing.
No, you are shrinking! Looking down, you gape at the slender limbs of a young boy. Maybe 13, the years melting away from your body like a candle in a flame. 12, 11, 10... you stop getting smaller, but the heat continues. Your skins darkens, then sprouts a fine black gary-brown fuzz that thickens into a full coat of fur. Fingers and toes merge into hooves, and you are thrown forward onto arms turned forelegs as your back and thighs change shape.
You feel your face push outward, scents and sounds becoming more intense. Above all, you smell the mare, and feel a deep need in your belly. Stumbling to her, your thick dark lips seek out and find the swollen teats of her udder, and pull the first squirt of milk into your mouth.
Part of you is still human, and you are both horrified and fascinated by this transformation. Horrified becuase you feel your humanity fading away with each mouthful of mare's milk, and fascinated because of the rich sensations of the newborne foal's body.