If you were the owner of Minecraft what one block or item or mob would you add and why?

If I were the owner of Minecraft I would add a new boss mob that would live in the nether in a rare structure, this boss would be like the devil with huge horns and red skin he would be huge and scaly and apon deathwould drop the devils horn that could be used to summon any mod (not boss) with just the click of a button making the use of spawn eggs in survival!