My husband, Christian Finnegan, is a stand up comedian and happens to be born on April Fool's Day. Dad drew him a card with a sweet note. (Below L to R is the Front, Inside Left and Inside Right). I have no idea why the front is more like a creepy Halloween card, but the inside is fun. It has a man* signing "Fool's Day" in ASL. I'm not sure that sign is universal, though.
*Or a lesbian? Or a punk? Those cheeks are awfully rosy.