Preheat oven to 400°. In mixing bowl combine crab, crawfish, onions and bell pepper. Add mustard, Worcestershire sauce, Tabasco and cheese. Combine water, butter and salt in a medium saucepan, bring mixture to a boil. Reduce heat to low; add flour and stir vigorously until mixture leaves sides of pan and forms a smooth ball. Remove saucepan from heat and allow mixture to cool slightly. Add eggs, one at a time, beating with a wooden spoon after each addition. Beat until batter is smooth. Add crab mixture. Stir well. Drop batter by heaping teaspoon onto an ungreased baking sheet. Bake at 400° for 15 minutes. Reduce heat to 350° and bake an additional 10 minutes. Serve puffs warm.