Not sure what you mean.
Polymorph is a keyword in 4e, for powers that change a target’s physical form in some way.
In most cases, none of your defenses or abilities change, and you are limited to certain types of actions.
Do you have a specific polymorphing power in mind? Class?
Specifcally I am playing a shifter barbarian who plans on taking the moonspeaker paragon path and i am wondering what the wolf for does specifically