Something interesting about Minecraft's mobs is that no friendly, helpful magic mobs exist. No Unicorns, no friendly dryads, no Pegasi, not even a friendly anthropomorphic animal character. I actually like this idea that the magic in Minecraft is a corruption on the world that comes from sources like the Nether and the End, and that it's the player's job to fight this corruption. It adds a nice, albeit fairly generic, lore to the game.