Alright so this is the first time I've ever done anything like this so bare with me please. I once read a fanfic of just Peeta going into the Games and not Prim. And something I remember specifically is that in his games he killed a polar bear. And the Capitol I believe made a coat of off the fur from the bear for him to wear. I read it a LONG time ago so it's all pretty fuzzy to me. But I think you guys can find it because from what I've seen you are all amazing! Hope you can find it!
The story you are looking for is When the Moon Fell in Love with the Sun by Mejhiren.