So this is a question about the polymorph and true polymorph spells. Both spells include in their description an explanation as to what happens to the gear of the target of the polymorph spells ...
The target’s gear melds into the new form. The creature can’t activate, use, wield, or otherwise benefit from any of its equipment.
... but nothing about what happens if you take away a part of the creature, like a feather, does it disappear once the spell is over, do you keep it ?
This is probably a subjective matter who's gonna gather subjective answers, but I don't mind. I have found nothing in the SAC or the erratas about that and even tho my current GM has ruled that I could keep the feather of the hummingbird I had polymorphed into, but I also do feel like it's a debate I could have with every future DM ... might as well see what RPG Stack Exchange thinks ?
