There is a variety of chicken dishes, I dont think you will find neck bone on the ship, though there will be a variety of pork dishes offered on the menu. As far as crab legs, I honestly do not remember seing crab legs on the menu, but Carnival is changing their menus so could be. However, you will find things like calamari, scallops, shrimp and lobster dishes. Can't say that I have seen cat fish on the menu or at the buffet either, there will be fish offered. Most of the food in the restuarants are more like what you would find in the finer restuarant on land. My husband loves his "grits" and we have found them on the buffets occassionally, but they do serve them in the restaurants, but I have noticed they have them on the menu as "hominy grits".
Just take this opportunity to try any foods that you have never tasted before, if you dont like it, just order something else, it is an experience to sample new dishes.