From Minecraft Wiki
id: Entity ID. This tag does not exist for the Player entity.
Pos: 3 TAG_Doubles describing the current X,Y,Z position of the entity.
Motion: 3 TAG_Doubles describing the current dX,dY,dZ velocity of the entity in meters per tick.
Rotation: Two TAG_Floats representing rotation in degrees.
The entity's rotation clockwise around the Y axis (called yaw). Due south is 0. Does not exceed 360 degrees.
The entity's declination from the horizon (called pitch). Horizontal is 0. Positive values look downward. Does not exceed positive or negative 90 degrees.
FallDistance: Distance the entity has fallen. Larger values cause more damage when the entity lands.
Fire: Number of ticks until the fire is put out. Negative values reflect how long the entity can stand in fire before burning. Default -20 when not on fire.
Air: How much air the entity has, in ticks. Fills to a maximum of 300 in air, giving 15 seconds submerged before the entity starts to drown, and a total of up to 35 seconds before the entity dies (if it has 20 health). Decreases while underwater. If 0 while underwater, the entity loses 1 health per second.
OnGround: 1 or 0 (true/false) - true if the entity is touching the ground.
NoGravity: 1 or 0 (true/false) - if true, the entity will not fall if in the air.
Dimension: Only known to be used in <player>.dat to store the players last known location along with Pos. All other entities are only saved in the region files for the dimension they are in. -1 for The Nether, 0 for The Overworld, and 1 for The End.
Invulnerable: 1 or 0 (true/false) - true if the entity should not take damage. This applies to living and nonliving entities alike: mobs will not take damage from any source (including potion effects), and cannot be moved by fishing rods, attacks, explosions, or projectiles, and objects such as vehicles and item frames cannot be destroyed unless their supports are removed. Note that these entities can be damaged by players in Creative mode.
PortalCooldown: The number of ticks before which the entity may be teleported back through a nether portal. Initially starts at 300 ticks (15 seconds) after teleportation and counts down to 0.
UUIDMost: The most significant bits of this entity's Universally Unique IDentifier. This is joined with UUIDLeast to form this entity's unique ID.
UUIDLeast: The least significant bits of this entity's Universally Unique IDentifier.
CustomName: The custom name of this entity (text component [1.13]). Appears in player death messages and villager trading interfaces, as well as above the entity when your cursor is over it. May not exist, or may exist and be empty.
CustomNameVisible: 1 or 0 (true/false) - if true, and this entity has a custom name, it will always appear above them, whether or not the cursor is pointing at it. If the entity hasn't a custom name, a default name will be shown. May not exist.
Silent: 1 or 0 (true/false) - if true, this entity will not make sound. May not exist.
Passengers: The data of the entity riding. Note that both entities control movement and the topmost entity controls spawning conditions when created by a mob spawner.
- See this format (recursive).
Glowing: 1 or 0 (true/false) - true if the entity has a glowing outline.
Tags: List of custom string data.