(Nether Biome) The Black Lagoon

This biome would be kind of like a lava swamp.

It would generate with a new nether tree that is immune to fire. It would have lava filled along an entire layer, and there would be platforms scattered around that can be stood on. However, some of the platforms will break upon being stood on, and the player would fall into the lava. These blocks that break can be pointed out since they emit thick black particles, which is where the biome gets its name. Special lava creatures would spawn here, as well as Ghasts and Magma Cubes.