The fruit of an ancient plant that the Beeba tribe grows in order to tame Wingapedes.
The Ancient Fruit is a variety of fruit grown by the Beeba near the Hydra Marshes. It is fed to Wingapedes to tame them and allow transport on their backs. Serge obtained some after escaping the Temporal Vortex; he used it to control a Wingapede in Home World to travel to Gaea's Navel and back.
From: Key Items (Chrono Cross)