Future mob?

As seen on Notch's Tweet. It spoke of a new Mob. If you rearrange the letters. It says Ender-Dragon? I think. I believe another MineCraftian found this out too. This dragon will be able to ride if you have a Bonemeal. [Just like a Wolf with a bone, it'll fall in love with you and follow you, except in this, you can ride on it and tell it where to go if you have reins.] Also. I heard of a 1.9 Leak. In the leak you can Construct Reins. Can this possibly mean a new way to ride Pigs? [Dragons too of course]. I also heard of a Horse Leak possibly. So how will the Reins play into this?