This is a rather silly question, but as I was working on my spreadsheet for my druids wild shape forms, I saw that the Eagle entry also listed the summon monster version. The interesting thing is that the summon monster version is
N Small celestial/ fiendish animal
Which to me, reads as being a valid target for wild shaping once I am 6th level, as its still an animal. So by this reasoning if a creature has a listed template on it, and has an entry somewhere, am I allowed to wild shape into templated versions?
Druid Wild Shape ability
At 4th level, a druid gains the ability to turn herself into any small or Medium animal and back again once per day. Her options for new forms include all creatures with the animal type. This ability functions like the beast shape I spell, except as noted here. The effect lasts for 1 hour per druid level, or until she changes back. Changing form (to animal or back) is a standard action and doesn’t provoke an attack of opportunity. The form chosen must be that of an animal the druid is familiar with.
So at no point anywhere in the wild shape, beast shape, elemental body, or plant shape information, does it say you cant choose a version which includes a template. However I expect that if the template made a change to something, the spell you are using must still allow that feature, so larger size from a template unless you can wild shape into that size.
A typical druid can't use wild shape to assume a form with a template
It's buried in the description of the school of Transmutation under the subschool Polymorph: "Polymorph [subschool] spells cannot be used to assume the form of a creature with a template or an advanced version of a creature." Since the druid's supernatural ability wild shape functions like the spells beast shape I et al., the supernatural ability wild shape shares the spells' prohibitions against assuming a form possessing a template.