private ItemStack PortalGun(){
  ItemStack is = new ItemStack(Material.CROSSBOW, 1);
  is.addEnchantment(Enchantment.QUICK_CHARGE, 3);
  ItemMeta im = is.getItemMeta();
  im.addItemFlags(ItemFlag.HIDE_ENCHANTS);
  im.setDisplayName(main.Color("&9Portal Gun"));
  is.setItemMeta(im);
  return is;
}

if(e.getBow().isSimilar(PortalGun())){
  Entity entity = player.getWorld().spawnEntity(player.getLocation(), EntityType.CAT);
  e.setProjectile(entity);
}