Rainbow Dash and the Monster Horse Cock

Rainbow Dash grows a massive horse cock. It isn't nearly as awesome as you'd think.

At the beginning of her final semester of high school, Rainbow Dash suddenly, inexplicably, grows a monstrously huge horse cock. Neither science nor magic can explain it. It rapidly takes over her entire life.

Some people want to study it. Some people want to play with it. Rainbow Dash just wants it to go away--preferably without any horrifying pain.