Here is where you'll find all sorts of awesome Minecraft stuff!
Open up your command line, and type in this:
Mojang even created some accounts with custom heads mapmakers can use.
The name format is MHF_mob.
So MHF_Ghast will give you this:
Open up Snapshot 15w14a and the first thing you'll see is the lack of the Singleplayer button. In this snapshot you can only have one world, and it has to be called 'There can only be one'. Survival mode becomes Existence, and Hardcore is gone forever. (This is the Love and Hugs update after all)
When you load the world you'll see that everything seems a bit...pink. That's because a new shader has been added called love, which gives everything a nice red tint. If you go near a body of water, you'll see that it is bubbling with hearts. Every particle in the game is now a heart!