A living Entity is one that has health and that can die.
Unlike IEntityLivingBase however, players aren't IEnitiyLiving objects!

It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import.
import crafttweaker.entity.IEntityLiving;

IEntityLiving extends IEntityLivingBase. That means all functions available to IEntityLivingBase objects also are available to IEntityLiving objects.

ZenGetter	ZenSetter	Тип
ZenGetter attackInterval	ZenSetter ​	Тип int
ZenGetter attackTarget	ZenSetter attackTarget	Тип IEntityLivingBase
ZenGetter canBeSteered	ZenSetter ​	Тип bool
ZenGetter canPickUpLoot	ZenSetter canPickUpLoot	Тип bool
ZenGetter canSpawnHere	ZenSetter ​	Тип bool
ZenGetter getLeashedToEntity	ZenSetter ​	Тип IEntity
ZenGetter isAIDisabled	ZenSetter isAIDisabled	Тип bool
ZenGetter isAIDisabled	ZenSetter isAIDisabled	Тип bool
ZenGetter isColliding	ZenSetter ​	Тип bool
ZenGetter isLeashed	ZenSetter ​	Тип bool
ZenGetter isLeftHanded	ZenSetter isLeftHanded	Тип bool
ZenGetter isNoDespawnRequired	ZenSetter ​	Тип bool
ZenGetter maxSpawnedInChunk	ZenSetter ​	Тип int
ZenGetter ​	ZenSetter moveForward	Тип float
ZenGetter ​	ZenSetter moveStrafing	Тип float
ZenGetter ​	ZenSetter moveVertival	Тип float
ZenGetter renderSizeModifier	ZenSetter ​	Тип float

Requires no parameters.
Returns nothing.

ZenScript
 Copy
ebtLiv.playLivingSound();

Requires no parameters.
Returns nothing.

ZenScript
 Copy
ebtLiv.spawnExplosionParticle();

Requires an IEntityEquipmentSlot object and a float.
Returns nothing.

ZenScript
 Copy
ebtLiv.setDropChance(IEntityEquipmentSlot slot, float chance);

Requires no parameters.
Returns nothing.

ZenScript
 Copy
ebtLiv.enablePersistence();

First method requires an IEntity object, a boolean and returns nothing. Second method requires two booleans and returns nothing.
Third method requires an IPlayer object and returns a bool.

ZenScript
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ebtLiv.setLeashedToEntity(IEntity enttiy, boolean sendAttachNotification);
ebtLiv.clearLeashed(boolean sendPacket, boolean dropLead);
ebtLiv.canBeLeashedTo(IPlayer player);