Aliens vs Predator mod (for 1.7.2) by Ri5ux
This mod adds in the three main species involved in the movies as mobs, aliens, predators, and of course a few human variants. And of course you will need something to kill those enemies with, so we added a bunch of new weapons yo obliterate them with!
mobs survival tools
Dungeon Mobs is intended to be a more dangerous analogue to Mo' Creatures.
Hamster Mod by RazzleberryFox
This mod adds in Hamsters to minecraft! Cute, fluffy, cheeks full of seeds… you know hamsters!
Lava Monsters by FatherToast
This is a small mod that adds a new hostile monster to the game that spawns in lava and spits fireballs at you.
Lycanites Mobs by Lycanite (Richard Nicholson)
Lycanites Mobs is a project that adds a wide range of new mobs to Minecraft. The mod adds a group of mobs to each specific biome type as well as other locations such as from Fire or Lava.
Mob Properties by FatherToast
This mod allows you to customize all mobs, vanilla or otherwise, with completely configurable drops, attributes, equipment, potion effects, and even NBT data.
Pet Bat by AtomicStryker
PetBat mod allows you to tame a bat that will accompany you and help you fighting mobs.
mobs survival opensource