An Overworld Ghast!
From my Biome Swap resource pack, it's my entry into the contest :D

I started with the idea of making a grass-block ghast, but decided to make the eyes into underground lakes and the mouth into a lava pool. From there I mixed in bedrock and stone style textures, as well as some gold and diamond.

Check out the full pack, which includes the ghast_shooting texture as well!
[​full pack]