//Вспомогательные переменные
List<LivingEntity> mobs = new ArrayList<LivingEntity>();
HashMap<LivingEntity, Player> check = new HashMap<LivingEntity, Player>();
//Создание моба
LivingEntity mob = (LivingEntity) loc.getWorld().spawnEntity(loc, EntityType.CREEPER);
mobs.add(mob);
check.put(mob, p);
//Проверка цели
@EventHandler
public void mobTarget(EntityTargetEvent e){
if (e.getTarget().getType()!=EntityType.PLAYER) return;
LivingEntity ent = (LivingEntity) e.getEntity();
if (mobs.contains(ent)) {
Player p = check.get(ent);
Player pc = (Player) e.getTarget();
if (pc.equals(p)) e.setCancelled(true);
}
}