The Mother Ship for pikmin. Pikmin live inside the onions. There are only three kinds that Captain Olimar has to find: Red, Yellow, and Blue Onions. Only pikmin of the same color can enter an onion. At night the onions take flight and travel with Captain Olimar. Pikmin inside the onion are completly safe from danger. As of now, there is no Purple or White onion.
After there were 100 pikmin on the field, the pikmin onion stop throwing pikmin seeds out into the field.