Entity NBT
About how entity NBTs and the different types there are.

NBT
What is NBT
NBT or Named Binary Tag, is a tree-like structure that Minecraft uses to store entity data. This data can include 
attributes, 
definitions, and 
identifier information. This information can control things what the entity looks like, how it interacts with the world, and its behavior. Knowing how NBT works can give you insight on certain things you may encounter or want to achieve. NBT however is not the entity itself but instead a snapshot of its runtime components that we can load to make a copy of the entity. In bedrock all NBT is encoded in little-endian which is important if you want to extract it into a stringified format like the one below.

Entity NBT Format
NBT FORMAT (WIP)
Legend
Icon
Meaning
String
Short
Long Array
Long
JSON Object
Integer Array
Integer
Float
Double
Byte Array
Byte
Boolean
Array
Format Tree
root label
Where the NBT tree starts
identifier
Defines entity type ID. 
Example: "minecraft:pig".
definitions
Adds or removes components from the from the baseline entity components. These are entity mostly specific. + adds a component not on the base entity and - removes a component on the base entity.
Example: "+minecraft:can_ride_default"
UniqueID
Unique numerical ID of the entity used to identify it from others of it type.
Example: "-4294967289".
Pos
Shows numerical values as to the position of the entity in 3D space.
X
Shows the X position of the entity.
Y
Shows the Y position of the entity.
Z
Shows the Z position of the entity.
Rotation
Defines the orientation angle of the entity. 
Yaw
The orientation of the entity rotating clockwise around the X axis. (No more than 360°)
Pitch
The orientation of the entity rotating up and down along the Y axis. (No more than ±90°)
Motion
Defines the momentum assigned to a given entity.
dX
Defines momentum along the X axis.
dY
Defines momentum along the Y axis.
dZ
Defines momentum along the Z axis.
CustomNameVisible
Shows a custom name given to an entity regardless if you are looking directly at them or not.
LastDimensionId
Last dimension visited by the entity. (Seemingly deprecated)
FallDistance
Distance the entity has fallen.
Fire
Number of ticks till the fire on the entity is extinguished.
OnGround
Defines if an entity is in the state of being on the ground. (Not falling)
Invulnerable
Makes the target entity unable to be harmed by any natural source. Entities with this tag cannot be moved by fishing rods. Creative players can deal damage regardless of the tag being applied to the target entity.
PortalCooldown
Number of ticks before a given entity can use a nether portal again.
IsGlobal
Defines if the entity can function in unloaded chunks.
IsAutonomous
Exact use is unknown.
LinksTag
Defines a connection between a ride and a rider. 
entityID
Unique numerical ID of the rider entity the ride entity has linked to.
Example: "-3410204032983".
linkID
Numerical value used to determine which rider is which on the ride entity. (Starts at 0 and increments by 1 for each passenger) 
LootDropped
Defines if an entity can or cannot drop loot. This is applied after the entity has received the Dead tag to ensure it doesn't drop loot more than once.
Color
Defines an entities color type. For example the difference between a black cat and a siamese cat is this value.
Color2
Defines an entities secondary color. Only tropical fish use this.
Strength
Defines how much a llama can carry. ( 3 * number = Items carriable ) 
StrengthMax
Does the same thing as "
Strength" seemingly.
Sheared
Defines whether a sheep is sheared. 
IsIllagerCaptain
Defines whether an entity is an Illager Captain.
OwnerNew
Shows new owner ID. This is often for projectiles.
 
Example: "-4294967295"
OwnerID
Shows current owner ID. This is often for projectiles.
 
Example: "-4294967295"
Sitting
Defines whether an entity is sitting.
IsBaby
Defines whether an entity is in its baby variant.
IsTamed
Defines whether an entity is tame.
IsTrusting
Defines whether an entity is trusting of the player.
IsOrphaned
Defines whether an entity is spawned without parents.
IsAngry
Defines whether an entity is hostile when it is normally neutral.
IsOutOfControl
Is set to true when a player is controlling it and it is a ship.
Variant
Defines entity variant type.
MarkVariant
Defines the mark variant of an entity. 
Saddled
Is set to true when a player has mounted it and it is a living entity.
IsChested
Defines if a working animal such as a horse carries a chest on its back.
ShowBottom
Defines whether an end crystal shows the bedrock slab below it. (Used in the end dimension's crystals)
IsGliding
Defines whether an entity is in the gliding state with an elytra.
IsSwiming
Defines whether an entity is in the swimming state.
IsEating
Defines whether an entity is eating something.
IsScared
Defines whether an entity is in the scared state.
IsStunned
Defines whether ravager is stunned.
IsRoaring
Defines whether ravager is roaring.
SkinID
Defines a villager/zombie villagers skin texture.
Persistent
Defines if an entity can or cannot despawn when out of the player's mob spawning radius.
Tags
Holds player applied tags that an entity has. (these are applied via /tag)
tag (not a real namespace)
Tag identifier
 
Example: "CanopyAdmin"
CustomDisplayTile
Set to true when a minecart is displaying a custom block.
DisplayBlock
Set to true when a minecart is displaying a custom block.
block (not a real namespace)
Block ID of a block to be displayed within the minecart.
 
Example: "minecraft:dirt"
DisplayOffset
Number of pixels the display block of a minecart is offset along the Y axis.
Willing
Defines if a villager is willing to breed or not. This value is set to false for a period of time after breeding.
SpawnedByNight
Defines if a mob was spawned naturally by the night cycle or not.
ItemInHand
Defines what item an entity holding.
Count
Count of items in the hand.
Name
Defines the item type in the hand.
 
Example: "minecraft:crossbow"
WasPickedUp
Defines if the entity got the item by picking it up.
Damage
This may say damage but it does not store the damage for the item.
CanPlaceOn
Defines what the item be placed on when the user is in Adventure mode.
block (not real namespace)
Block ID it can be placed on.
 
Example: "minecraft:stone"
CanDestroy
Defines what the item can break when the user is in Adventure mode.
block (Not real namespace)
Block ID it can destroy.
 
Example: "minecraft:stone"
tag
Defines additional properties.
Mainhand
Defines what item is in the entities mainhand.
item (not a real namespace)
Item object.
Count
Count of items.
Name
Defines the item type.
 
Example: "minecraft:crossbow"
WasPickedUp
Defines if the entity got the item by picking it up.
Damage
This may say damage but it does not store the damage for the item.
CanPlaceOn
Defines what the item be placed on when the user is in Adventure mode.
block (not real namespace)
Block ID it can be placed on.
 
Example: "minecraft:stone"
CanDestroy
Defines what the item can break when the user is in Adventure mode.
block (Not real namespace)
Block ID it can destroy.
 
Example: "minecraft:stone"
tag
Defines additional properties.
Offhand
Defines what item is in the entities offhand.
item (not a real namespace)
Item object.
Count
Count of items.
Name
Defines the item type.
 
Example: "minecraft:crossbow"
WasPickedUp
Defines if the entity got the item by picking it up.
Damage
This may say damage but it does not store the damage for the item.
CanPlaceOn
Defines what the item be placed on when the user is in Adventure mode.
block (not real namespace)
Block ID it can be placed on.
 
Example: "minecraft:stone"
CanDestroy
Defines what the item can break when the user is in Adventure mode.
block (Not real namespace)
Block ID it can destroy.
 
Example: "minecraft:stone"
tag
Defines additional properties.
limitedLife
Sets a number of ticks before an entity is deleted. 
TradeTier
Defines a villagers trading level.
TradeExperience
Defines a villagers experience progress to next level.
canPickupItems
Defines if an entity can pick up items.
hasSetCanPickupItems
Set to true if the canPickupItems component has been set by the game.
HurtTime
Duration an entity has the invulnerable tag set to true after taking damage. This also controls the duration in which the entity is red after taking damage.
DeathTime
Duration an entity executes its death animation to the player before deletion. 
Dead
Defines if the entity has died.
AttackTime
Ticks before attack cooldown is complete.
Surface
True if the entity has spawned naturally on the surface. (IE, surface cap)
portal_transition
Internally used entity NBT for transitioning entities between dimensions. This is used because when an entity enters the portal it's reference is destroyed, so it needs some way to know the conditions in which it entered the portal.
axis
Saves the the axis in which the portal the entity entered is facing. (1 = z, 2 = x)
dimension
Defines which dimension the entity is coming from (0 = overworld, 1 = nether, 2 = end)
X
Shows the X position the entity entered a portal at.
Y
Shows the Y position the entity entered a portal at.
Z
Shows the Z position the entity entered a portal at.
NaturalSpawn
True if the entity has spawned naturally via cave or surface cap.
TargetID
Unique numerical ID of an entity that this entity is targeting for some purpose.
ActiveEffects
Lists the entities potion effects it has on it.
Effect (Not A Real Namespace)
Effect json object
Ambient
True if the effect was applied by a beacon. This is to make the particles less invasive on the screen.
Amplifier
The potion effect level. 0 is level 1.
DisplayOnScreenTextureAnimation
Displays a screen animation when an effect is applied. This is used in bad omen, totems, and the hero of the village to display the floating icon once you get the effect.
Duration
Number of ticks before the effect wears off.
DurationEasy
Number of ticks before the effect wears off for Easy mode.
DurationNormal
Number of ticks before the effect wears off for Normal mode.
DurationNormal
Number of ticks before the effect wears off for Hard mode.
Id
Numerical potion Id.
 
example: 28
ShowParticles
Defines if particles are shown or not.
FactorCalculationData
Unknown usage
change_timestamp
Unknown
factor_current
Unknown
factor_previous
Unknown
factor_start
Unknown
factor_target
Unknown
had_applied
Unknown
had_last_tick
Unknown
padding_duration
Unknown
IsInRaid
Boolean only present in villagers that defines if the villager is currently in a raid.
ReactToBell
Defines if a villager will react to a bell ringing and go to its home or not.
TargetCaptainID
Unique numerical ID of the Illager captain of a patrol. Used by pillagers in patrols.
Example: "-4294967289".
isCreative
Defines if a given projectile was fired from a player in creative mode. (Only projectiles have this)
enchantPower
Defines the power level given to an arrow by the power enchantment on the shooters bow.
enchantPunch
Defines the punch level given to an arrow by the power enchantment on the shooters bow.
enchantFlame
Defines the flame level given to an arrow by the power enchantment on the shooters bow.
enchantInfinity
Defines the infinity level given to an arrow by the power enchantment on the shooters bow.
MobEffects
List of effects that a given entity can pass onto others. This does not apply to itself. (Used in area effect clouds and tipped arrows)
Effect (Not A Real Namespace)
Effect json object
Ambient
True if the effect was applied by a beacon. This is to make the particles less invasive on the screen.
Amplifier
The potion effect level. 0 is level 1.
DisplayOnScreenTextureAnimation
Displays a screen animation when an effect is applied. This is used in bad omen, totems, and the hero of the village to display the floating icon once you get the effect.
Duration
Number of ticks before the effect wears off.
DurationEasy
Number of ticks before the effect wears off for Easy mode.
DurationNormal
Number of ticks before the effect wears off for Normal mode.
DurationNormal
Number of ticks before the effect wears off for Hard mode.
Id
Numerical potion Id.
 
example: 28
ShowParticles
Defines if particles are shown or not.
FactorCalculationData
Unknown usage
change_timestamp
Unknown
factor_current
Unknown
factor_previous
Unknown
factor_start
Unknown
factor_target
Unknown
had_applied
Unknown
had_last_tick
Unknown
padding_duration
Unknown
auxValue
Defines a numerical ID for what arrow type it is, whether it is tipped and with what potion.
 
example: 23    (Healing II)
SelectedInventorySlot
Numerical ID of a slot selected in a players inventory.
SelectedContainerId
Numerical ID of a container selected by the player. 
Sleeping
Defines if the player is sleeping or not.
SleepTimer
Defines for how long the player has been sleeping in a bed.
SpawnBlockPositionX
Defines the X location for the players respawn block like a bed or respawn anchor.
SpawnBlockPositionY
Defines the Y location for the players respawn block like a bed or respawn anchor.
SpawnBlockPositionZ
Defines the Z location for the players respawn block like a bed or respawn anchor.
SpawnDimension
Defines what dimension the player's spawn point is located in.
SpawnX
Defines the X location for the players respawn point.
SpawnY
Defines the Y location for the players respawn point.
SpawnZ
Defines the Z location for the players respawn point.
EnchantmentSeed
RNG seed for enchantment tables to deterministically give you the same enchantments.
RideID
Unique numerical ID of an entity that the player is riding.
LeftShoulderRiderID
Unique numerical ID of an entity that the player has on its left shoulder.
RightShoulderRiderID
Unique numerical ID of an entity that the player has on its right shoulder.
PlayerGameMode
Numerical ID of the gamemode the player is in currently.
PlayerLevel
How many experience levels the player has.
PlayerLevelProgress
How much experience progress a player has to the next level.
Not all NBT tags are used in a standard entity, this just includes all known NBT labels and their known purpose.

NBT definitions