The new form may not have higher Hit Dice than the caster's level.
The caster retains his or her own intelligence, hit points, saving throws, and attack probabilities.
Physical capabilities of the new form (e.g. strength, physical attack forms, modes of movement) are acquired.
Non-physical special abilities (e.g. immunities, breath weapons, spell casting) are not acquired.
While polymorphed, the caster is unable to cast spells.
The spell cannot be used to duplicate the appearance of a specific individual.
If the caster dies while polymorphed, he or she returns to his or her original form.