More posibilities how to kill mobs/players
SFENCE

Add more posibilities how to kill mobs and/or players, like traps, throwable TNT, etc.

Visual Harm 1Ndicators
Mantar

HP bars for mobs/players

Traders
Sokomine

Configurable mobs/NPC which can trade for you.

Wisps
ElCeejo

Adds non-entity mobs called Wisps

Cube Mobs
Xanthus

Adds various cube mobs with different abilities using mobkit.

Not So Simple Mobs
TenPlus1

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

Mobs Redo API
TenPlus1

Simple and feature rich API to quickly add mobs into your world.

Large Slugs
jwmhjwmh

Adds node-based slug mobs to your world

Mobs Monster
TenPlus1

Adds many types of monster.

Balrog Sword MT 5.4
DragonWrangler

allows those using the old mobs balrog mod to have balrog swords

3D Armor Mobile
LandarVargan

Adds a command to bring up a formspec that allows mobile users to put on armor

Zoonami 3D Mobs
isaiah658

Adds 3D monster mobs to Zoonami.

Living Slimes
EmptyStar

Adds living slime mobs to Minetest

Alive AI
AiTechEye

Advanced survivor ai mobs (npc, monsters and more)

Sky Mobs
TenPlus1

Sky Mobs for Mobs Redo

MobConf
zeuner

Place, remove and configure Mobs (for now: NPCs) using chatcommands

Extreme Randomizer
NO11

Randomises crafting, mob and block drops.

Mobs Takodachi
Silver Sandstone

Adds takodachis.

Mobs Ghost Redo
TenPlus1

Adds ghosts.

MFSM Multiple Finite State Machine
Sumi

Allows for multple states to be active, while maintaining typical state machine behavior. Good for gamestate and mobs.

mime (flux's fork)
fluxionary

adds a monster mimicking its surrounding nodes.

Mob BiomeDb Mapper
Neuromancer

Allows mobs to spawn in biomes that don't support them (Using info from BiomeDb)

Mob Crab (Beta)
Can202

Adds Crabs.

Mob Horse
TenPlus1

Adds rideable horse

Water Mobs
TenPlus1

Water Mobs for Mobs Redo

Disable Mob Damage for Advanced Trains
Silver Sandstone

Prevents trains from damaging mobs.

Mob Biome Mapper
Neuromancer

Allows mobs to spawn in biomes that don't support them.

Mobs Skeletons
TenPlus1

Adds three skeletons to the world.

balrog (flux's fork)
fluxionary

adds balrogs.

Invisiblocks
TenPlus1

Add invisible barrier, light and mob wall into game with new tool

Mesebox
johalun

Mobile storage box powered by Mese

Mob Core
mt-mods

A Mob API meant to expand upon mobkit and bring easy to use features for creating new Mobs.

Wilhelmines Living Caves Mobs
Liil

adds mobs to the caves of your world

Banshee
ElCeejo

Adds Banshees, a ghostly mob that haunts pine forests

Nether Mobs
Dirkfried

Add monsters and dragons to your nether world.

Creatura
ElCeejo

A performant, semi-modular, Animal focused mob API

Mobile Crosshair
GreenXenith

It's a crosshair for mobile.

GetName
kevins

Adds an API and tool to generate random names for NPCs, mobs, and places.

Common Mob Interface
Byakuren

A standard modding interface for interacting with mobs

Moblib
LMD

Low-level high-performance entity library