Gibdos are the corpses of Hylians that have been animated by the Enslave spell. Since the Enslave spell is used in their creation, they will collapse if the Healing spell is cast on them.
The Legend of Zelda, The Adventure of Link, A Link to the Past, Link's Awakening, The Ocarina of Time, Majora's Mask, and the characters Link, Zelda, Impa, and all other persons, places, and things in Hyrule, as well as the land of Hyrule, itself, are copyright Nintendo of America, Inc. Krystofor claims no rights for the materials, and this game may not be used for profit in any way.