Makes underground MUCH harder! All mobs below the layer specified get 'Cursed' and gain new abilities. Older Versions at the bottom!
ALL zombies below layer 12 (where diamonds can be seen) become Stromlings, from the shut-down MMO LEGO Universe. They have two health, sprinting speed and stone-sword strength.
Drops Maelstrom Bricks (a crafting material), Stromling Blade (stone sword strength diamond with speed effect but decreases health to a heart, rare drop) and normal zombie drops.
Skeletons below layer 6 become regular Wither Skeletons, making the Wither easier to get.
Silverfish below layer 12 become Landsharks, and can eat through stone to get to you. They drop Dust and (rarely) a Rektaxe.
The Baby Maelstrom Soul Pet is used by fusing the energy of 64 Stromlings into one item. Although he can't do much yet, it can convert Cobblestone into Smooth Stone, clear out Zombies in a 5-block radius, can play with you (Smooth Stone Slabs, is all I'm saying) and can be used [and disposed of :( ] like an Ender Pearl, and can also be picked up into your inventory. To use him again as a pet, drop him as you would any normal item (Press Q by default).
Baby Creeper Soul
The Baby Creeper Soul Pet is used by compressing 32 Dust. He doesn't do anything yet (except show that you were able to find and kill 32 landsharks), but can be sacrificed for decoration (placing him, but why'd you waste such a hard-to-get item?)
MORE MOBS TO COME...
The Maelstrom Brick is a Nether Brick which can be used to make a pet!
Dust is Gunpowder which can do the same!
The Rektaxe is a Stone Pickaxe which sets your health to 3 hearts, makes you slower but is unbreakable.
MORE ITEMS TO COME...