He makes her into an anthro cow.

Over the years, Tom had been interested in quite a few anthro animal designs. But with the chance to impose one on Sarah, he knew exactly what to try first. Rubbing the coin’s version of his wife’s face, he wished, “Overnight, Sarah is going to transform into my exact fantasy of her as an anthropomorphic cow girl. She’ll be freaked out and confused at first, but also believe any explanation I give her for it. Over time, mental changes fitting her new body will take effect, and the world at large will be totally okay with her changes and she won’t lose her job or face discrimination for it.”

With the wish properly made, Tom waited for her to get home, treated her well when she was there, enjoyed some pretty good sex, then the two went to bed together, Tom already getting hard thinking of what changes were going to come over his wife in the morning. Sure enough, when the sun arose next, he turned over in bed to see her already awake and looking in a mirror.