Swell Foop by Piers Anthony

This compilation of excerpts centers on a magical realm where Cynthia Centaur, a transformed human, embarks on a quest to rescue the Demon Earth and restore gravity, which is fading, by finding Rings of Xanth and a powerful artifact called the Swell Foop. Along the way, she navigates Challenges that test her ingenuity and fortitude, often encountering punning wordplay and diverse magical beings like zombies, demons, and centaurs. The narrative also follows Jaylin, a Mundane girl, whose daydream about a "swell foop" inadvertently connects her to this mission, requiring her to travel to Xanth and master the Ring of Void. The story explores themes of identity, destiny, and the interplay between mortal and magical realms, culminating in the successful activation of the Swell Foop and the rescue of the Demon Earth, although with lingering implications for the characters' personal lives and the universe itself.