Enter the Heart Drop mod. Upon death, all mobs now drop hearts, which when picked up by the player will heal them one heart each. The number of hearts dropped by each mob is determined by its max health, so the harder they are to kill the more hearts they will drop.
Even with no other mods installed, it still would be the perfect companion to any survival world with natural regen disabled, and also works great all by itself just to give you some quick health as you fight your way out of the zombie horde.
# Configuration file
general {
# A number between 0 and 1. Every time a player attacks a boss and it loses this percentage of its health, it will drop a heart.
# For example, at 0.1 (10%) a boss with 100 health will drop a heart every time a player attack brings its health below 90, 80, 70, etc.
# Default: 0.1
D:BossHeartDrops=0.1
# Set to true and punch an entity to see its name.
# Only useful for building the entity blacklist.
# Default: false
B:DebugEntities=false
# A comma-separated list of all entities you do NOT want to drop hearts.
# For example, if you don't want livestock to drop hearts, use: Pig,Sheep,Cow,Chicken
S:EntityBlackList=
# The number of ticks before hearts will despawn.
# Default: 6000
I:HeartDespawn=6000
# A number between 0 and 1 that determines how often entities drop hearts upon death.
# If set to 1, hearts will drop 100% of the time.
# Default: 1
D:HeartDropChance=1.0
# A number between 0 and 1 that modifies the amount of hearts dropped by entities on death.
# Is ignored when singleHeart is set to 'true'
# Default: 0.5
D:HeartDropModifier=0.5
# The number of extra hearts you get for every level of the looting enchantment on your weapon.
# Default: 1
I:LootHearts=1
# If set to true, entities will only ever drop one heart at a time.
# HeartDropModifier will be ignored.
# Default: false
B:SingleHeart=false
# If set to true, you will directly consume the life-force of your enemies.
# No hearts will drop, but you will still heal.
# Default: false
B:VampireMode=false
}
This mod should be automatically compatible with all resource packs since it pulls the texture directly from the "tame heart" particle effect.
Mineuniverse