The Red One was a red, inter-galactic Federal Police Cruiser that Stitch stole from Gantu's ship in Lilo & Stitch. When the fleet escorting the ship attacked the Red One, damaging it, Stitch used the Red One's hyperdrive to escape. However, as the damage the fleet caused to the Red One had disabled its navigation system, when the Red One came out of hyperspace, it crashed on Kauai, Earth. Stitch survived the crash, but the Red One apparently blew up upon impact.
The Red One's design appeared to vary in all of its appearances: in the original film it was red with a vertical white stripe, in the TV series it was red with a horizontal white stripe, and in Stitch! it had a more triangular design.