A Cow

The enclosure changed to be a barnyard, with a dog house, barn, and feeding trough.

Sakura got to all fours, her eyes in a reverse eye cross.

"Moo..." she droned, now a cow.

Naruto watched as the pink-haired beauty lowered her head to eat some grass, and he made a quick wish to make it so that any woman who became an animal wouldn't have any negative side effects from that animal's diet, so Sakura was good to eat grass.

"Hey, Naruto!" a voice called. "Nice zoo!"