"Alright ladies" said the magician, looking at the two dozen courtiers lined up on the grassy field "you can start by removing your clothes. Cows, as you know, don't wear anything." Queen Beth's obese ladies began to strip.
The magician cracked his knuckles, a habit he had before beginning a serious work of magic. Fortunately, transformations of people who actually wanted to be transformed were far easier than those of unwilling victims. The former Queen's ability to transform the unwilling was one reason the magician, who did not in the slightest degree think of himself as a hero, had given her a wide berth. And all the fat meant that there would be plenty to work with. Easy money, he licked his lips.
"Very well, ladies, now assume the position, down on your hands and feet." With some complaints, the ladies assumed the position. "Don't worry," said the wizard "you'll feel much more comfortable as your body changes. Now give me some moos!"
First tentatively, then more confidently, the ladies began to moo as the wizard began his incantations. The changes began slowly and subtly--a patch of brown hair here, a hand turning to a hoof there. The moos grew deeper and more bovine. The ladies settled into their position, which began to feel natural as their arms and legs grew leaner, stronger and longer. As the first lady in waiting's face turned into a cow's muzzle, she bent down and began to nibble at the grass. Soon the others joined her. Where the noble ladies had been was now a herd of cows grazing in the field. The farmers who had paid to take possession of the new cows started to take their new property away (the first lady in waiting had ensured that her new owner would be the farmer who already owned the Queen).
The magician smiled. What the ladies hadn't known is that over the course of the first few months, their new cow brains would rewrite their personalities, essentially irrevocably eliminating their elven and human selves. Sex with bulls and bearing calves would accelerate the process, as he had already hinted to the farmers. By the time the noble families realized it, he would be long gone with the considerable sums of money he had been paid, at least that was the plan.