Lead

Leads, also known as leashes, are items used to leash and lead passive mobs.

Mobs
Wandering traders drop 2 leads when detached from trader llamas.

Leashing mobs


a lead on a mob will tie it to the mob, allowing it to be moved by the player. Multiple mobs can be held by leads at once, but require one lead per mob led.

It is possible to leash the following mobs:


 * Cat
 * Chicken
 * Cow
 * Dolphin
 * Donkey
 * Fox
 * Iron golem
 * Llama (incl. Trader Llama)
 * Mooshroom (both variants)
 * Horse
 * Mule
 * Ocelot ‌
 * Parrot
 * Pig
 * Polar bear
 * Rabbit
 * Sheep
 * Squid
 * Snow Golem
 * Wolf

Additionally, villagers, wandering trader and hostile mobs can be leashed using a map or NBT editor.

With a mob on a lead, it on any type of fence (not wall) will attach any leads you are holding to the fence with a visible knot. Multiple leads may be attached to one fencepost. A mob will tend to stay within 5 blocks of the fencepost.

A lead can also be attached to a boat

Pressing the control on the mob again, hitting the knot, or removing the fence post will break the lead(s). Leads will also be broken if the knot is hit by arrows. Whenever a lead is removed or broken, it will drop as an item at the location of the mob – except if pressing use item control on the mob in Creative mode. A lead will not break if the animal that it is attached to dies.

A lead will stretch a maximum of 10 blocks before breaking.

A lead will not prevent a mob which would otherwise despawn, such as a squid, from despawning.

If the player is holding a lead connected to a mob, walks through a nether portal, then walks back through it, the player will still have the leads attached to the mob. However, if the mob walks into a nether portal, the leads are broken and dropped as items in the other dimension.

If the player uses a lead on a compatible mob within a boat, the mob will leave the boat, avoiding the need to break the boat.

If the player leashes a mob to a fence and the chunk unloads (either by walking too far away, or travelling to another dimension via portal - e.g. travelling to the Overworld from The Nether or vice versa), the lead will break and drop as an item, leaving the mob free to wander around.

Data values
Lead knots have entity data which define various properties of the entity.

Trivia

 * The lead is named as “leash” in the texture file.
 * If a player goes to sleep while holding a mob on a lead, the lead will remain attached.
 * If the player attempts to land after flying on Creative mode with a mob leashed, the mob will take damage as if it fell (with the exception of ocelots, snow golems, cats, iron golems, parrots and chickens) unless under slow falling effect or it lands on a slime block or in water.
 * When using the /replaceitem to put a lead in a player's head slot, it looks like the player is wearing a monocle.

Gallery
Leine Rienda Laisse Lasszó Guinzaglio リード 끈 Leidtouw Smycz Поводок 拴绳