Polymorph, Greater

This spell functions as polymorph except that it allows the creature to take on the form of a dragon or plant creature. If you use this spell to cause the target to take on the form of an animal or magical beast, it functions as beast shape IV. If the form is that of an elemental, the spell functions as elemental body III. If the form is that of a humanoid, the spell functions as alter self. If the form is that of a plant, the spell functions as plant shape II. If the form is that of a dragon, the spell functions as form of the dragon I. The subject may choose to resume its normal form as a full-round action; doing so ends the spell.