From publisher blurb:
Beast Form Secrets
The beast shape spell family is far from exotic. Not because many wizards eagerly prepare this spell (they do not, and they have reasons for that), not because many magi choose to fight as animals (they typically prefer blades and spellcasting), but because druids spend their lives polymorphing to anything that runs, swims, flies or burrows.
While there are many magic enhancements for animal and monstrous forms, few of them fully explore the fact that any shapechanging is curiously close to lycanthropy, making a druid in wild shape and a “monstrous” lycanthrope very similar from a certain point of view.
Another interesting aspect of changing shapes is that many alternate forms prevent any use of classic spells (at least as long as you do not have Natural Spell Feat), but still they might have their own magic of growls and yowls, hardly usable for humanoids. While not many examples of such magics have been identified—most being supernatural and spell-like abilities of magical beasts rather than proper spells usable by adventurers—some of such spells are listed.
This and much more is discussed in this issue of Spell Books!