Only ten Li'l-Oinks can be located in the pen at a time. Once the eleventh Li'l-Oink enters the pen, the first and oldest Li'l-Oink leaves. Once that Li'l-Oink leaves, an item is left behind. The item that is dropped depends on the breed of the Li'l-Oink. This methods is one of the ways to obtain Ultra Shrooms and Jammin Jellies. This is also a way to get infinite Repel Gel, considered the rarest item in the game.