The texture file mummy.png is 64x64, but you have it so the model uses a 64x32 texture. To use a 64x64 file with the mummy, change this line (line 11):
this(0.0F, 0.0F, 64, 32);
to:
this(0.0F, 0.0F, 64, 64);
Sorry if Im late, but I had a very similar problem. In your log file it says this:
This means Minecraft doesn't know the save id of the Tile Entity. You need to assign it. Idk if Forge has a different way of doing it, but I added this line to the mod initiator:
TileEntity.addMapping(TileEntityFoo.class, "Foo");
The first parameter is your TileEntityClass, and the second parameter is the save game id.
Note: I actually didn't have a problem, but when I see a stack trace in the Eclipse console, I know somethings wrong