Hidden deep within Pikmin: Sinister Incinerator is one, completely optional Pikmin variety called the Blue Bulbmin. These ultra-rare creatures are led by Blue Bulbmin leaders, similar to regular Bulbmin. If you're able to track down the location of this rare creature and can defeat it in battle (it's actually a tough enemy) and you have enough room for the five blue bulbmin it had following it, you can whistle them to your side. Resistant to all elements and cool-looking as well, Blue Bulbmin can leave the dungeon with you. There are four separate Blue Bulbmin leaders scattered in deep dungeons throughout the world, giving you a maximum of twenty Blue Bulbmin that you can hold in your ship at a time.