Entity metadata

Mobs

Mobs are spawned via 0x18 Mob Spawn. There are two extra mob types in the code that refer to mobs classes that can never spawn: Mob and Monster (they are always subclasses, aka another more specific type).

Type	Name	x, z	y
48	Mob	N/A	N/A
49	Monster	N/A	N/A
50	Creeper	0.6	1.8
51	Skeleton	0.6	1.8
52	Spider	1.4	0.9
53	Giant Zombie	3.6	10.8
54	Zombie	0.6	1.8
55	Slime	0.6 * size	0.6 * size
56	Ghast	4	4
57	Zombie Pigman	0.6	1.8
58	Enderman	0.6	2.9
59	Cave Spider	0.7	0.5
60	Silverfish	0.3	0.7
61	Blaze	0.6	1.8
62	Magma Cube	0.6 * size	0.6 * size
63	Ender Dragon	16.0	8.0
64	Wither	0.9	4.0
65	Bat	0.5	0.9
66	Witch	0.6	1.8
67	Endermite	0.4	0.3
68	Guardian	0.85	0.85
90	Pig	0.9	0.9
91	Sheep	0.9	1.3
92	Cow	0.9	1.3
93	Chicken	0.3	0.7
94	Squid	0.95	0.95
95	Wolf	0.6	0.8
96	Mooshroom	0.9	1.3
97	Snowman	0.4	1.8
98	Ocelot	0.6	0.8
99	Iron Golem	1.4	2.9
100	Horse	1.4	1.6
101	Rabbit	0.6	0.7
120	Villager	0.6	1.8

Objects

Objects are spawned via 0x17 Spawn Object/Vehicle. See Object Data for more details.

ID	Name	x, z	y
1	Boat	1.5	0.6
2	Item Stack (Slot)	0.25	0.25
10	Minecart	0.98	0.7
11 (unused since 1.6.x)	Minecart (storage)	0.98	0.7
12 (unused since 1.6.x)	Minecart (powered)	0.98	0.7
50	Activated TNT	0.98	0.98
51	EnderCrystal	2.0	2.0
60	Arrow (projectile)	0.5	0.5
61	Snowball (projectile)	0.25	0.25
62	Egg (projectile)	0.25	0.25
63	FireBall (ghast projectile)	1.0	1.0
64	FireCharge (blaze projectile)	0.3125	0.3125
65	Thrown Enderpearl	0.25	0.25
66	Wither Skull (projectile)	0.3125	0.3125
70	Falling Objects	0.98	0.98
71	Item frames	varies	varies
72	Eye of Ender	0.25	0.25
73	Thrown Potion	0.25	0.25
74	Falling Dragon Egg	0.98	0.98
75	Thrown Exp Bottle	0.25	0.25
76	Firework Rocket	0.25	0.25
77	Leash Knot	0.5	0.5
78	ArmorStand	0.5	2.0
90	Fishing Float	0.25	0.25

Since Release 1.6, all minecarts are spawned with object type 10 and their functionality is then specified in the Object data within the packet. Also, their visual appearance may be sent via the Entity Metadata packet.

Entity Metadata

Entity Metadata Format

Note that entity metadata is a totally distinct concept from block metadata. All entities must send at least one item of metadata, in most cases this will be the health item.

The entity metadata format is quirky dictionary format, where the key and the value's type are packed in a single byte.

To parse, repeat the following procedure:

1. Read an unsigned byte
2. If this byte == 127, stop reading
3. Decompose the byte.
   The bottom 5 bits (0x1F) serve as an identifier (key) for the data to follow.
   The top 3 bits (0xE0) serve as a type.
4. Read and unpack based on the type (below)

Type	Meaning
0	Byte
1	Short
2	Int
3	Float
4	UTF-8 String (VarInt prefixed)
5	Slot
6*	Int, Int, Int (x, y, z)
7	Float, Float, Float (pitch, yaw, roll)

*Not currently used

In C-like psuedocode:

do {
    item = readByte();
    if (item == 0x7F) break;
    var index = item & 0x1F;
    var type = item >> 5;
    
    if (type == 0) metadata[index] = readByte();
    if (type == 1) metadata[index] = readShort();
    if (type == 2) metadata[index] = readInt();
    if (type == 3) metadata[index] = readFloat();
    if (type == 4) metadata[index] = readString();
    if (type == 5) metadata[index] = readSlot();
    if (type == 6) {
        var vector;
        vector.x = readInt();
        vector.y = readInt();
        vector.z = readInt();
        metadata[index] = vector;
    }
    if (type == 7) {
        var rotation;
        rotation.pitch = readFloat();
        rotation.yaw = readFloat();
        rotation.roll = readFloat();
        metadata[index] = rotation;
    }
} while (true);

To create the byte, you can use this: (Type << 5 | Index & 0x1F) & 0xFF

Entity

Index	Type	Meaning
0	Byte	Bit Mask	Meaning
		0x01	On Fire
		0x02	Crouched
		0x08	Sprinting
		0x10	Eating/Drinking/Blocking
		0x20	Invisible
1	Short	Air

Living Entity

^{Extends Entity}

Index	Type	Meaning
2	String	Name Tag
3	Byte	Always Show Name Tag
6	Float	Health
7	Int	Potion Effect Color
8	Byte	Is Potion Effect Ambient
9	Byte	Number of Arrows in Entity
15	Byte	Whether the entity has no ai.

Ageable

^{Extends Living Entity}

Index	Type	Meaning
12	Byte	Entity's Age (Negative = Child)

ArmorStand

^{Extends Living Entity}

Index	Type	Meaning
10	Byte	Bit Mask	Meaning
		0x01	Small Armorstand
		0x02	Has Gravity
		0x04	Has Arms
		0x08	Has Baseplate
11	Float, Float, Float (pitch, yaw, roll)	Head position
12	Float, Float, Float (pitch, yaw, roll)	Body position
13	Float, Float, Float (pitch, yaw, roll)	Left Arm position
14	Float, Float, Float (pitch, yaw, roll)	Right Arm position
15	Float, Float, Float (pitch, yaw, roll)	Left Leg position
16	Float, Float, Float (pitch, yaw, roll)	Right Leg position

Human

^{Extends Living Entity}

Index	Type	Meaning
10	Unsigned Byte	Skin flags
16	Byte	Bit Mask	Meaning
		0x02	Hide Cape
17	Float	Absorption Hearts
18	Int	Score

Horse

^{Extends Ageable}

Index	Type	Meaning
16	Int	Bit Mask	Meaning
		0x02	Is Tame
		0x04	Has Saddle
		0x08	Has Chest
		0x10	Is bred
		0x20	Is Eating
		0x40	Is Rearing
		0x80	Mouth Open
19	Byte	Value	Type
		0	Horse
		1	Donkey
		2	Mule
		3	Zombie
		4	Skeleton
20	Int	Bit Mask	Meaning
		0x00FF	Value	Color
			0	White
			1	Creamy
			2	Chestnut
			3	Brown
			4	Black
			5	Gray
			6	Dark Down
		0xFF00	Value	Style
			0	None
			1	White
			2	Whitefield
			3	White Dots
			4	Black Dots
21	String	Owner Name
22	Int	Value	Type
		0	No Armor
		1	Iron Armor
		2	Gold Armor
		3	Diamond Armor

Bat

^{Extends Living Entity}

Index	Type	Meaning
16	Byte	Is Hanging

Tameable

^{Extends Ageable}

Index	Type	Meaning
16	Byte	Bit Mask	Meaning
		0x01	Is Sitting
		0x04	Is Tame
17	String	Owner Name

Ocelot

^{Extends Tameable}

Index	Type	Meaning
18	Byte	Ocelot Type

Wolf

^{Extends Tameable}

Index	Type	Meaning
16	Byte	Bit Mask	Meaning
		Flags from Tameable
		0x02	Is Angry
18	Float	Health
19	Byte	Begging
20	Byte	Collar Color

Pig

^{Extends Ageable}

Index	Type	Meaning
16	Byte	Has Saddle

Rabbit

^{Extends Ageable}

Index	Type	Meaning
18	Byte	Rabbit Type

Sheep

^{Extends Ageable}

Index	Type	Meaning
16	Byte	Bit Mask	Meaning
		0x0F	Value	Color
			0	White
			1	Orange
			2	Magenta
			3	Light Blue
			4	Yellow
			5	Lime
			6	Pink
			7	Gray
			8	Silver
			9	Cyan
			10	Purple
			11	Blue
			12	Brown
			13	Green
			14	Red
			15	Black
		0x10	Is Sheared

Villager

^{Extends Ageable}

Index	Type	Meaning
16	Int	Value	Profession
		0	Farmer
		1	Librarian
		2	Priest
		3	Blacksmith
		4	Butcher

Enderman

^{Extends Living Entity}

Index	Type	Meaning
16	Short	Carried Block
17	Byte	Carried Block Data
18	Byte	Is Screaming

Zombie

^{Extends Living Entity}

Index	Type	Meaning
12	Byte	Is Child
13	Byte	Is Villager
14	Byte	Is Converting

Zombie Pigman

^{Extends Zombie}

Blaze

^{Extends Living Entity}

Index	Type	Meaning
16	Byte	On Fire

Spider

^{Extends Living Entity}

Index	Type	Meaning
16	Byte	Climbing

Cave Spider

^{Extends Spider}

Creeper

^{Extends Living Entity}

Index	Type	Meaning
16	Byte	State (-1 = Idle, 1 = Fuse)
17	Byte	Is Powered

Ghast

^{Extends Living Entity}

Index	Type	Meaning
16	Byte	Is Attacking

Slime

^{Extends Living Entity}

Index	Type	Meaning
16	Byte	Size

Magma Cube

^{Extends Slime}

Skeleton

^{Extends Living Entity}

Index	Type	Meaning
13	Byte	Value	Meaning
		0	Normal
		1	Wither

Witch

^{Extends Living Entity}

Index	Type	Meaning
21	Byte	Is Agressive

Iron Golem

^{Extends Living Entity}

Index	Type	Meaning
16	Byte	Is Player Created

Wither

^{Extends Living Entity}

Index	Type	Meaning
17	Int	Watched Target
18	Int	Watched Target
19	Int	Watched Target
20	Int	Invulnerable Time

Boat

^{Extends Entity}

Index	Type	Meaning
17	Int	Time Since Hit
18	Int	Forward Direction
19	Float	Damage Taken

Minecart

^{Extends Entity}

Index	Type	Meaning
17	Int	Shaking Power
18	Int	Shaking Direction
19	Float	Damage Taken / Shaking Multiplier
20	Int	Bit Mask	Meaning
		0x00FF	Block Id
		0xFF00	Block Data
21	Int	Block Y Position
22	Byte	Show Block

Furnace Minecart

^{Extends Minecart}

Index	Type	Meaning
16	Byte	Is Powered

Item

^{Extends Entity}

Index	Type	Meaning
10	Slot	Item

Arrow

^{Extends Entity}

Index	Type	Meaning
16	Byte	Is Critical

Firework

^{Extends Entity}

Index	Type	Meaning
8	Slot	Firework Info

Item Frame

^{Extends Entity}

Index	Type	Meaning
8	Slot	Item
9	Byte	Rotation

Ender Crystal

^{Extends Entity}

Index	Type	Meaning
8	Int	Health