Alex Bellos, Ed Pegg and fellow math-funsters: Inspired by a Lego brick, I've discovered a new weakly-aperiodic three-dimensional monotile. Its proof of aperiodicity is reasonably simple, with the only non-trivial lemma being the unique factorisation of the Gaussian integers. A discussion, complete proof and picture are included here: http://cp4space.wordpress.com/2013/08/23/new-aperiodic-monotile/ Other tiles which admit tilings of a similar type are Schmitt's original tile (1988) and the convex Schmitt-Conway-Danzer tile. Sincerely, Adam P. Goucher