Heavy Gibdo Sword is a heavy Sword used by Gibdos. It is based on the unnamed and unobtainable swords wielded by ReDeads in The Legend of Zelda: Twilight Princess & Link's Crossbow Training. They were first named in the non-canon Hyrule Warriors.
In the Japanese version of Twilight Princess, ReDeads were known as Gibdos. These enemies wielded large heavy swords that they used to attack Link, however due to their weight they had trouble wielding them. The swords disappeared when a ReDead was defeated and thus unobtainable by Link.
Heavy Gibdo Swords appear as swords used by Gibdos and as the Gibdo's Silver Material drop. They can be used to craft badges and Apothecary mixtures. ReDead Knights also wield similar swords, but these are unobtainable as ReDead Knights drop ReDead Knight Ashes as their Silver Material.