More posibilities how to kill mobs/players
SFENCE

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

Traders
Sokomine

Configurable mobs/NPC which can trade for you.

Visual Harm 1Ndicators
Mantar

HP bars for mobs/players

Raids
DragonWrangler

Allows server owners or server admin to start mob raids to attack settlements or players

Moblib
LMD

Low-level high-performance entity library

Mesebox
johalun

Mobile storage box powered by Mese

Mobs Animal
TenPlus1

Adds farm animals.

Alive AI
AiTechEye

Advanced survivor ai mobs (npc, monsters and more)

Mobs Redo API
TenPlus1

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

Wilhelmines Living Caves Mobs
Liil

adds mobs to the caves of your world

Not So Simple Mobs
TenPlus1

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

Mob Crab (Beta)
Can202

Adds Crabs.

Spawners
SaKeL

Adds spawners for mobs, dungeons, temples and ores.

Mob Core
mt-mods

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

Wisps
ElCeejo

Adds non-entity mobs called Wisps

GetName
kevins

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

3D Armor Mobile
LandarVargan

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

Water Mobs
TenPlus1

Water Mobs for Mobs Redo

Balrog Sword MT 5.4
DragonWrangler

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

Disable Mob Damage for Advanced Trains
Silver Sandstone

Prevents trains from damaging mobs.

Mob Limiter
Neuromancer

removes mobs over max count near players with configurable settings

Mob Horse
TenPlus1

Adds rideable horse

Invisiblocks
TenPlus1

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

Extreme Randomizer
NO11

Randomises crafting, mob and block drops.

Mobkit
mt-mods

Entity API

Climbing Pick
lag01

Tool to climb, double jump, and do good damage to mobs.

Mobs Ghost Redo
TenPlus1

Adds ghosts.

Zoonami 3D Mobs
isaiah658

Adds 3D monster mobs to Zoonami.

Hud Hider
Hito Hito

Make your hud invisible on mobile.

Living Slimes
EmptyStar

Adds living slime mobs

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.

Banshee
ElCeejo

Adds Banshees, a ghostly mob that haunts pine forests

Skeleton
AntumDeluge

A skeleton mob.

More Danger
Twinsonian

Scaling difficulty multiple games/mob apis. Based on the difficulty mobs will have faster movement speed, more damage and more health.

Lategame Amulets
Comet

A cohesive progression system that builds on Mobs Monster

Mob Biome Mapper
Neuromancer

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

Large Slugs
jwmhjwmh

Adds node-based slug mobs to your world

MobConf
zeuner

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

Common Mob Interface
Byakuren

A standard modding interface for interacting with mobs