I was listening to some music discs on Minecraft and thought that maybe you could make one of my mob idea's sound files sound like the broken disc? I thought of it because at the beginning it sounds like a monster chasing someone.....I can never listen to that disc for more than 5 seconds :(

Nightmares in Reality, huh? Well, if you are going for a spooky, horrific feel then I might have a few ideas.

Mobs:
Demon Spawn (A demon-like mob that spawns in the Nether dimension that wield Stone Swords)
Poltergeist (A ghost that is transparent and can disappear at will)
Necromancer (A cloaked being that can spawn skeletons, zombies, and poltergeists. Boss, maybe?)
Chupacabra (A blood-sucking monster that spawns in Deserts)
Goat (Not a scary mob, but attract Chupacabras and run from the player when hit)
Possessed Goat (An innocent goat possessed by the power of The Deranged)
The Deranged (An insane man that spawns Possessed mobs. Another Boss?)
Possessed mobs include Sheep, Squid, Cow, Chicken, Pig, Bat, Villager, Mooshroom, and Ocelot.

Items/Blocks:
Chupacabra Fang (used to make Fang Dagger)
Goat Blood (used to make Chupacabra Lure)
Blood Bag (A small bag that can be consumed to heal all health. Tames Chupacabra)
Goat Pelt (Can be used to make armor)
Necromancer Cloak (A form of armor that allows the player to spawn undead mobs)
Deranged Star (An item used to make a Possessor block)
Possessor (A beacon-like block that possesses nearby passive mobs)
Fang Dagger (A weapon as strong as a Stone Sword)
Chupacabra Lure (When held, it attracts Chupacabras)
Goat Pelt Armor (As strong as Leather Armor, but allows faster sprinting)

Hope you like my ideas :3

here is a question why dont u post whats IN the mod

Bosses or mutants.

They drop special items you need to proceed to new areas or dimensions