Teeny Ships are smaller, simpler versions of the Gummi Ship found in Kingdom Hearts II and Kingdom Hearts II Final Mix. They can be used to attack alongside you or deflect enemy attacks. The Teeny System is made available after completing Mission 1 of Phantom Storm.
There are always two Teeny Ships on the Regular and Original Gummi Blueprints. However, if you make your own blueprints, you can produce your own Teeny Ship blueprint. You can also choose whether to have one or two teeny ships alongside you.
Teeny Ship Blueprints