I was exploring the cave systems on creative and peaceful, and I came across a sealed room made of cobblestone and mossy cobblestone. There was a chest in the room as well, with a few supplies such as string, bread, and a fishingrod. And then there's this creepy cage thing that's on FIRE and has a small spinning figure inside it that looks like a zombie.

What am I supposed to do? I don't know whether I should leave it alone or break it or what!