Rigged Riddle

A “riddle” that the person answering can not reasonably know the answer too, as it depends on information only the asker should know. Obviously the person asking the riddle tends to win.

Literature

 * In The Hobbit, Bilbo asked Golem “What have I got in my pocket?” Understandably, Golem asserts that this riddle isn't fair.

Oral Tradition, Folklore, Myths, Religion, and Legends

 * In Norse Mythology One time while Odin was disguised he was in a riddle contest. Odin won when he asked what was the thing Odin whispered in the ear of Baldr’s corpse. Obviously, when Odin posed this "riddle", his opponent saw through Odin's disguise.
 * In The Bible, one time Samson came across a cow corpse with honey inside and used that as the basis of the riddle.
 * What is Rumplestiltskin’s name?