Looking for a template-granting possessing creature... or is there the equivalent of Marvel's symbiote?

[JiCi]

Does Pathfinder have a fiend, an undead, an ooze or whatever creature that 1) can possess another creature and 2) grant a template as long as the possession is on-going?

I stated the symbiote as an example, but I'm looking for any creature with a similar power.

[Val'bryn2]

What you're looking for is the Synthesist Summoner, you can have an Unfettered Eidolon so it can exist as it's own being.

[deuxhero]

There are a few templates for a creature that has been taken over by spores or the like, but nothing I can think of that comes on and off.