JoshBlueMoon may have already made a concept of a movement based sculk prototype, this is my twist of it, less horror though. My Hollow is rather a corrupted sculk caused by a reaction with light gel, it doesn't kill or assimilate the sculk but rather upgrades it. Hollowed holes are the vein varient of the Trypophobic Hollow Block, which cannot be broken because they're holes in soon to be Hollow blocks. Normal Hollow Blocks don't have holes in them (it doesn't infect or corrupt, it rather "corrodes"). Transforms from: sculk
In Trypophobic Hollow Blocks, can Maloresin be found and can be obtained with a shovel. Maloresin is an item that can be used with furnaces and blast furnaces to make Malocite ingots. Maloplasm is a glowing red fluid only found in this biome as pools and the Nightmare dimension as oceanwater, it doesn't deal any damage but it does give you a negative effect, possession. Possession will make you lose control of what you do and make you hostile to any mob that you see. Maloplasm, like other fluids, can be bucketed.
The reincarnation of the scrapped sculk jaws, Hollow jaws are like beartraps, except they have tastebuds, not only does it summon the Hollowed, but it also corrodes nearby blocks (which it sucks the blood the bled out of you to grow), each bite deals 2 and a half hearts (it bites 3 times). Tastevines are the sculk sensors of the hollow, all they need is a touch of a single mob and they summon the Hollowed, nothing with prevent them from doing this because they are literally tastebuds on vines. Tasteroot Hollow Blocks are the source of Tastevines, the maximum range of growth is 8 blocks.
basically the warden but upgraded and mutated, it has higher senses in smell and hearing (downside is that LOUD noises stun it, like explosions, sonic booms, etc.), what it used to be can be seen in the blue areas, the claws, feet, and mouth, but its ribcage is gone because it doesn't need souls anymore, it needs flesh. Instead of the sonic boom, it has a tendril attack from the holes in its chest, which isn't really an attack but is rather a detection method. Health: 325 hearts/650 hp, transforms from: the warden