Who transforms Odysseuss sailors into pigs?

The answer to this is Circe. She was able to turn Odysseus’ crew by adding a magical potion to the food that she served to the crew. Odysseus was warned, and he set out in order to save his crew. He was told that he needed to protect himself from Circe’s magic.

He used the herb moly and through his various actions, he was able to save his men. He also made the effort to go back to the area until the possible routes were suggested to him by Circe. Circe even gave him some directions on the things that should be done.