Preheat oven to 300 degrees.
Line a large baking sheet with parchment paper. Set aside.
In a large bowl toss together Chex, pretzel sticks, goldfish, oyster crackers, nuts and pepitas.
In a small saucepan, melt butter oven medium heat. When butter is melted remove from heat and stir in Old Bay, worchestershire and cayenne until well blended.
Pour mixture over Chex mixture in bowl. Toss well to coat.
Spread on prepared baking sheet. Bake for one hour, tossing every 15 minutes.
Remove from oven and let cool on tray.
Place in airtight container. Snack mix will last for about one week.