Harry Potter and the Half-Blood Prince
by J.K. Rowling
Moaning Myrtle is the ghost of a Ravenclaw student who was killed by the Slytherin Basilisk in the Chamber of Secrets in 1943. She likes to moan and cry and wallow in self-pity in the girls' bathroom on the second floor, though she does occasionally visit the boys' bathroom. We discover in Book 6 that she has befriended Draco Malfoy, who often visits her in despair and in tears.