Minecraft wiki entry for History, associated text:  AttackTime: Number of ticks the entity's "invincibility shield" is lasting after the entity was last struck.
 DeathTime: Number of ticks the entity has been dead for. Controls death animations.
 Health: Amount of health the entity has. Players and enemies normally have up to 20 health. Livestock has up to 10 health.
 HurtTime: Unknown, maybe time invincible after being hit