Online Fake Client Plugin

Some days ago i played a bit on the Lifeboat's Skywars server and i noticed the "kit-players".
I was thinking how to make a plugin that create a "non-movable" (hope this is the right word) player where you can also choose the name.
Also there was a feature: when you click on a "kit-player" (to buy it) in your client (only in your) appears 2 block: Emerald and Red Mushroom block (mean accept and cancel the "transition")

Can anyone explain how to do it please?

Thanks

Send a raw AddPlayerPacket

And for the feature?

Listen to DataPacketReceiveEvent.

PHP:

    public function spawnPlayer($pos, Player $p) {
            $pk = new AddPlayerPacket();
            $pk->clientID = 0;

Not exactly. This function spawns am existing player. We don't want to instantiate a Player in this case.

what is the function used then?

It is only used for internally spawning hidden players or something like that.

So how would you spawn a new player with name $name?

Set the field $AddPlayerPacket->username.

You can use the "Specter" plugin that is in development by @Falk

He meant to use them for purposes AI. A significant reason why you can't use it is that you can't make two specters with the same name.

Oh accually there is an advanced plugin for bukkit that can do this called 'Citizens'

IIt's good if someone can port it to PocketMine