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

Mobs Animal
TenPlus1

Adds farm animals.

Skeleton
AntumDeluge

A skeleton mob.

Moblib
LMD

Low-level high-performance entity library

More Danger
Twinsonian

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

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.

Wisps
ElCeejo

Adds non-entity mobs called Wisps

Alive AI
AiTechEye

Advanced survivor ai mobs (npc, monsters and more)

GetName
kevins

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

Balrog Sword MT 5.4
DragonWrangler

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

Mob Limiter
Neuromancer

removes mobs over max count near players with configurable settings

Mob Horse
TenPlus1

Adds rideable horse

Mobkit
mt-mods

Entity API

Climbing Pick
lag01

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

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

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.

Common Mob Interface
Byakuren

A standard modding interface for interacting with mobs

Large Slugs
jwmhjwmh

Adds node-based slug mobs to your world

Mob Core
mt-mods

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

Nether Mobs
Dirkfried

Add monsters and dragons to your nether world.

Throwable Bombs
DragonWrangler

adds a cave expansion tool, a throwable tnt stick, a throwable smoke bomb, and a mob throws tnt

Mobs NPC
TenPlus1

Adds simple NPC and Trader.

Mobs Redo API
TenPlus1

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

Grave
ElCeejo

Adds an eerie biome with multiple mobs.

MobConf
zeuner

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

Creatura
ElCeejo

A performant, semi-modular, Animal focused mob API

Wilhelmines Marinara Mobs
Liil

adds mobs to the marinara oceans

balrog (flux's fork)
fluxionary

adds balrogs.

Mobs Ethereal Bosses
PixelZone

Adds Bosses in biomes from the "Ethereal NG" and "Mineclonia" mods

Too Many Aliases
ThePython10110

Adds aliases to every item/node in MineClone to make them match MineCraft so you can stop forgetting that mcl_mobitems:ender_pearl should be mcl_throwing:ender_pearl.