It's Monday, April 1, and in this puzzle we're celebrating the birthday of a well-known Muggle constructor who, even though he's been with us for only a year, has made quite an impression on us all. And how better to celebrate his birthday than by solving a meta puzzle? Shout-outs to the always-generous AJK for test-solving, our MMM Maestro Peter Abide, and Joe Ross for his formidable formatting skills. Hope you enjoy this one as much as I did creating it.