The Fountain of Aging is a special fountain that is found on the most ancient sun just past Teddybear Junction. It was thought to be only a myth told as a child's fairy tale, until the Planet Express crew come across it to re-age themselves after being lowered in age by the special anti-aging tar. Leela took the book to the young Professor and with its help, the young Planet Express crew travelled to the fountain and were reverted to their more or less correct ages after they had been youthasized by the Bubbling Geezer's searing-hot tar pits. A duplicate of John A. Zoidberg's brother, Norman Zoidberg, dies from its effects because he spent too much time inside the fountain.
The Fountain of Aging is mentioned in a book called A Child's Garden of Space Legends.