pocketmine\entity\Living::initEntity PHP Method

    protected function initEntity()
    {
        parent::initEntity();
        if (isset($this->namedtag->HealF)) {
            $this->namedtag->Health = new ShortTag("Health", (int) $this->namedtag["HealF"]);
            unset($this->namedtag->HealF);
        }
        if (!isset($this->namedtag->Health) or !$this->namedtag->Health instanceof ShortTag) {
            $this->namedtag->Health = new ShortTag("Health", $this->getMaxHealth());
        }
        if ($this->namedtag["Health"] <= 0) {
            $this->setHealth(20);
        } else {
            $this->setHealth($this->namedtag["Health"]);
        }
    }

 public function initEntity()
 {
     $this->setMaxHealth(16);
     parent::initEntity();
     if (!isset($this->namedtag->Size)) {
         $this->setSize(mt_rand(0, 3));
     }
 }