Customize player

How can I despawn a player from every other player and let them instead see a pig and so on?

Seems to me like DisguiseMe but modified.. I will look onto it.

DisguiseMe doesnt seem work anymore and no I dont mean the outdated API

To hide him, simply use Player::hidePlayer($p);.

PHP:

foreach($this->getServer()->getOnlinePlayers() as $pl){
$pl->hidePlayer($player); // $player is the player you want to hide
}

Make sure to also hide him on PlayerJoinEvent from the Player that joins.

For the Pig, simply spawn one that follows the player(Of course, you have to create it)

As simple as that