Ms. Tomlin, after making sure the door was locked, closed the blinds on the door and windows. She took a deep breath and made a pose that looked like she was channeling a spirit. Soon, before your very eyes, Ms. Tomlin began to change. Soon, black fur began to grow on her arms and legs as he hair turned gray. She dropped on all fours as he fingers began to merge togeyher, until they had reformed into hard, black hooves. She slipped out of her heels as her feet followed suit. She began to gain a lot of body mass as the fur covered her torso. Her hips and butt grew to massive size as her clothes were torn off. Her spine started to push out as a long gray tail forced itself out her backside. Her neck began to expand upwards as her face started to change. Her ears grew more pointed as her face began to stretch out into an equine snout. The fur had covered her body entirely as she let out a powerful whinny. There, where your teacher once stood, was a larger-than-normal black mare.
"Holy cow!" you cried in your native horse tongue. "Ms. Tomlin, you're... you're..." "A horse, yes." she replied, now in horsespeak that would be incomprehensible to the human ear. "But... how?" Lindsey exclaimed. "Well, you see..." Ms. Tomlin began.