Skidbladnir

A Skidbladnir is a magical ship that one uses if they need to get somewhere without having to rent, borrow, or otherwise using a ship that is not one's own. They are named after the magical boat that the Norse Immortal Frey uses.

Properties
Each skidbladnir has two forms that are interchangeable with each other. The dormant form takes the appearance of a block of wood, about the width and thickness of a typical deck of cards, but twice the length (approximately 0.625x2.5x7 inches). However, when one says the Scandinavian word "þróast" (meaning unfold), that block of wood will expand into a full-sized Viking-style longboat. The figurehead is unique to the owner of the skidbladnir in question, as well as the name of the ship. A skidbladnir has the additional properties of changing size, depending on how many passengers need the ship, automatic steering, and the ability to travel through sea, sky, and land. Also, when the ship is no longer needed, it can switch back to its dormant form by saying the Scandinavian word "falt" (meaning fold).