Separate the boiled eggs - whites onto a plate and the yolks into a bowl. Smash the yolks with a fork until fine. Add mayo, relish, mustard, and cajun seasoning, stirring to blend well. Add mayo or seasoning to adjust creaminess or spice. Refrigerate everything for an hour. Assemble deviled eggs by spooning mixture into the wells of the egg whites. Top with a little extra seasoning and a fried shrimp.