What people don't know about minecraft is that, after you've beaten the enderdragon and wither... There's another boss.
Many people don't know because you first have to make a very complicated redstone construction, and even if you succeed in doing that, the chances that you'll survive are small. 99% doesn't make it....

What it is:
It's a witchdoctor that masters redstone. You summon it by making a redstone construction. After that, a temple will spawn, containing various traps.