Thaw the king crab if frozen, then remove the meat from the shells and shred into bite-sized pieces.
In a large mixing bowl, combine cream cheese, mayonnaise, Dijon mustard, lemon juice, garlic powder, Old Bay seasoning, and black pepper. Mix until smooth.
Gently fold in the king crab meat and chopped chives, being careful not to break the crab meat too much.
Fill a greased mini muffin tin with the crab mixture, filling each cup about three-quarters full.
Mix panko breadcrumbs with melted butter and sprinkle over the crab filling in each muffin cup.
Bake in a preheated oven at 375°F for 15-20 minutes until golden brown.
Let cool for a few minutes before removing from the tin and serve warm with lemon wedges.