Sea-mice were small mouse-like creatures that were able to live on land or underwater by morphing their paws into fins—and vice-versa—through a process known as . Although this species was originally from Alderaan, many had been known to occupy some areas of Kamino. Since this planet is covered entirely by water, most sea-mice inhabiting Kamino have lost their ability to use corpus mutatio. When, in 0 BBY, the planet Alderaan was destroyed by the Death Star, the sea-mice still able to use corpus mutatio were wiped out entirely.
Sea-mice were often used as food for pet sea eels or rollerfish.
The Kaminoan word for "sea-mouse" was iiaa.