Brain Coral is a creature from Brain Coral Pool in Xanth. Its talent is suggestion. It was first introduced in The Source of Magic.
Brain Coral has tremendous intelligence, magic, and conscience. It protected the Demon Xanth until he was released. Since it can not move, it operates through thought suggestions which seem to creatures like their own ideas. Its pool is used to store criminals, like Vadne, and other miscreants, like Chilk, Jama, Numbo, Potipher, Zink, and Horsejaw. Some people elect to retire in the pool like Murphy, Cynthia, and Griselda.
Novels: The Source of Magic, Castle Roogna, Ogre, Ogre, Man from Mundania, Isle of View, Question Quest, Harpy Thyme, Geis of the Gargoyle, Roc and a Hard Place, Xone of Contention, The Dastard, Swell Foop