Melt the butter in a large skillet (12") and add the onion, bell pepper and celery. Cook over a medium heat until translucent.
Add the chopped parsley and garlic and cook a further 2 minutes.
Set aside to cool while you peel the crabs. You should end up with about 1-½ lb of crab meat (lump and claw). Keep 8 of the crab's body shells.
Preheat the oven to 350°F.
Add this crab meat to the cooled skillet and gently toss, so to not break up the crab too much.
Add the mayonnaise, beaten egg, fresh lemon juice, worcestershire sauce, hot sauce, Creole Seasoning and Old Bay Seasoning. Gently toss this mixture together until evenly mixed.
Add the parmesan cheese and sliced green onions, again toss gently.
Take the crab shells you kept and wash them well under warm water.
Take the crab meat mixture and press into each crab shell, pile this high.
Sprinkle a little more of the crushed crackers that are left over each stuffed shell, then place a little slice of butter on top of each filled shell.
Sprinkle with a little paprika and place on a baking sheet.
Place the stuffed crabs in the oven, uncovered, for 30 minutes.
Remove and serve immediately.
Notes
Using boiled crabs really adds some great flavor to this dish. However, if you can't get them already boiled go ahead and purchase some crab meat from the store. Some people prefer their crab stuffing to be a little more like a dressing/stuffing texture and without the large lumps of crab meat. This is definitely personal preference. If you prefer the crab meat to break down feel free to stir the mixture vigorously - It won't take much.Using real crab shells (the back shells) to stuff the mixture into gives it a really authentic look.If you don't have crab tools to help break apart some of the tougher parts you could use a paring knife - be super careful though.Use lump crabmeat, claw crabmeat, meat from the crab legs (if they're big enough).... any crabmeat is great for this recipe.