A. Weil published two short papers/letters signed as X.X.X (Amer. J. Math. 79, 1957, 951-952) and R. Lipschitz (Ann. of Math. 69, 1959, 247-251) where he posed as an anonymous correspondent and the XIX century German mathematician residing in Hades respectively. Both letters are reprinted at the very end of the second volume of Weil's Collected papers.