It's just a lava texture. I made a box everywhere with clip_water. Then with Ctrl+Shift+Left Mouse Button selected the top of the entity, and I added the lava texture

So if you are in it, the game show you under water effect, and if you shot it, it has got water waves effect too

And I made some red + orange lights

The lava texture is not moving :S I tried to add that waving effect, but it never worked

I tried to move with script but that was too fake moving and it was ugly
