I finished a run a few weeks back and when went to play again I noticed had bunny ears. I didn't think much of it at the time and just thought it was cool until realized you can move in the cosmetic menu and there was other categories and had wondered why it didn't appear. my friend had asked how I got it so I checked google, reddit, youtube, and then here and found no information on it. now I could have just not searched hard enough but has anyone got this before? and while I do have a rough idea on how I may have gotten it im not certain.

So this glitch happens sometimes where your game data disappears and your cosmetics can also disappear which is what probably happened. Many people have got it before including me, you just have to grind it back.