Tod Allen

A friend of Bruce Wayne and Dick Grayson and a member of the Sportsmen's Club - a man well known for his love of practical jokes - who, having deduced largely on the basis of circumstantial evidence that Wayne and Grayson are secretly Batman and Robin, is unable to resist the temptation to bedevil Bruce Wayne by mailing him a series of letters, all signed with the pseudonym Mr. X, in which he teases Wayne about having unraveled the secret of his dual identity. Batman and Robin ultimately deduce that Allen is their tormentor and decide to confront him to learn the exact nature of his evidence. Allen, however, dies in a plane crash, taking his knowledge of the Dynamic Duo's secret identities with him.