Preheat the oven to 250°F. In a large bowl, combine melted butter, Cajun seasoning, and Worcestershire sauce. Add pretzels, nuts, and cereals, tossing to coat.
Spread the mixture on a cookie sheet and bake in the oven for 1 hour, stirring every 20 minutes for even baking. Allow the mixture to cool completely before transferring it to an airtight container for storage or serving.