Amulet of the Swan Princess

Somewhere in the world there is a lake, once every new moon when the moon has left the sky, the lake draws the wearer to it's dark and mysterious waters.  The closer the wearer gets to the lake, the stronger the pull is.  As soon as they enter the lake, the amulet begins to glow and the wearer begins to change, their feet become orange and webbed, their arms turn into white feathered wings, and they slowly morph into a swan!  They will stay morphed like that until the sun rises into the sky.  

The wearer of this necklace is cursed to turn into a swan.  Once they are wearing the amulet and the transformation has happened they can no longer remove the amulet.  They will be drawn to that lake every full moon until they learn how to control the curse and transformation.

The player when turned to a swan has a swimming and flying speed equal to their walking speed, they can't communicate with other people only with animals.  Their AC is also halved.