From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Freeza's Hoverchair (ポッド 搭乗, Poddo Tōjō; Literally meaning "Pod Boarding") is a floating egg-shaped vehicle that Freeza uses for transportation when he is not in his spaceship. Even though he is extraordinarily powerful and perfectly capable of walking, Freeza, in his first form, seems to prefer using the Hoverchair as a means of getting around. The reason is unknown, although it is possible he sees it as a status symbol.
Freeza was in his Hoverchair when he launched the Supernova that destroyed Planet Vegeta. Years later, he brought the Hoverchair with him to Planet Namek during his quest for the Dragon Balls. During this time, Freeza initially only left the Hoverchair once when outside, and this was when Ginyu brought him the Dragon Balls. Otherwise, Freeza did not leave the hoverchair except when inside his spaceship. After it was discovered that he required a password in order to summon the Eternal Dragon, Freeza flew in his Hoverchair to the home of Guru. Here he left the Hoverchair for the second time while outside his spaceship to confront the ancient Namekian.
Freeza left the Hoverchair behind when he left with Nail to fight a safe distance from Guru's home. He did not take it with him after defeating Nail and returning to his ship, and the Hoverchair remained parked outside of Guru's home until Planet Namek's destruction.
- In Dragon Ball Z: Bardock: The Father of Goku, the segmented portions on the sides and back of the Hoverchair can apparently fold down into scimitar-shaped "legs", allowing the Hoverchair to stand on the floor without the use of anti-gravity. Freeza only has the Hoverchair in this mode in the scene where Zarbon and Dodoria are debating the Saiyans' growing strength in his presence before the young Vegeta enters.
- It is shown that Freeza's brother, Coola, has a similar vehicle in Dragon Ball Z: Cooler's Revenge in the opening scene. Their father, King Cold, is not depicted as possessing such a Hoverchair, likely because Cold is simply too big. He instead has an ordinary throne within his own spaceship.