Preheat oven to 225 degrees. Line a 13 x 18-inch sheet pan with parchment paper.
In an extra large bowl, combine Crispix cereal, mini pretzels, oyster crackers, cheesy crackers, and goldfish.
In a medium bowl, whisk the melted butter, ranch dressing mix, brown sugar, Worcestershire sauce, and cayenne pepper together. Pour over the cereal/cracker mix and toss to coat well.
Spread in an even layer on prepared sheet pan and bake at 225 degrees for 1 hour, stirring every 20 minutes.
Allow to cool and store in an airtight container for up to a week.