Common Mob Interface
Byakuren

A standard modding interface for interacting with mobs

Wilhelmines Living Nether
Liil

Adds various creatures to your Nether.

Ocean
StarNinjas

Adds coral reefs, fish, decorative ocean blocks and much more!

UwU (MineClonia)
Psyco

Add UwU block, uwu crystal ores, uwu tools and more.

Water Mobs
TenPlus1

Water Mobs for Mobs Redo

Wilhelmines Living Caves Mobs
Liil

adds mobs to the caves of your world

Herobrine (for Voxel Libre)
epCode

This adds in to the game `Herobrine`, which will grief you in minor creative ways.

Zombies4Test ( Reload )
PixelZone

Adding zombies, structures and weapons to your world..

Wilhelmines Living Floatlands
Liil

Adds various prehistoric animals to your Floatland Zone, if you are using V7 Map Generator.

Guinea pig
DrPlamsa

Adds guinea pigs.

Mobs Ghost Redo
TenPlus1

Adds ghosts.

Simple Dialogs
Kilarin

Simple Dialogs allows you to add dialogs for npcs and other entities, controlled by an in game text file.

Not So Simple Mobs
TenPlus1

Adds a host of creatures into your world with new weapons too.

Doctor Who Tardis
Skivling

Adds various items, blocks, Daleks, and a working TARDIS from the sci-fi show Doctor Who.