Line two large baking sheets with parchment paper, wax paper or silicone mats.
Melt white chocolate and semi-sweet chocolate in two separate bowls in the microwave in 30 second intervals. Stir well between each heating until the chocolate is smooth and creamy.
Transfer the chocolate into 2 medium-tall thin glasses to dip the prezel rods in.
Let's make ghost pretzels
Dip a pretzel rod in the white chocolate, covering about 3/4 of the pretzel. Let the excess chocolate drip off and transfer the pretzel to the lined baking sheet.
Place the sheet in the refrigerator or freezer so the chocolate sets. This should take about 15 minutes.
Use a disposable piping bag fitted with a small tip to pipe on dark chocolate eyes and a rounded mouth.
To make Halloween sprinkle pretzels
Dip pretzel rods in semi-sweet chocolate, covering about 3/4 off the pretzel. Let extra chocolate drip off and move the pretzel to the lined baking sheet. Cover with Halloween sprinkles, jimmies or nonpareils.
Place the sheet in the refrigerator or freezer so the chocolate sets. This should take about 15 minutes.
Make spider web pretzels
Dip a pretzel rod in melted semi-sweet chocolate until 3/4 of the pretzel is covered. Allow excess chocolate to drip off and transfer to the lined baking sheet. Refrigerate to set, about 15 minutes.
Use a disposable piping bag fitted with a small tip to drizzle melted white chocolate to look like a spider web. Return to the refrigerator or freezer to set.
Finally, to make the spiders, pipe a large dot of semi-sweet chocolate on the pretzel rod. Use a toothpick to drag out a small amount of the chocolate to make 8 legs.
For the mummy pretzels
Fill a disposable piping bag fitted with a small tip with melted white chocolate. Drizzle the chocolate back and forth over 3/4 of the preztel rod to resemble mummy wrappings.
Add two candy eyeballs towards the top of the pretzel rod. Refrigerate for about 15 minutes to allow the chocolate to set.
Notes
If you don't have disposable piping bags and tips, use a small ziploc bag and snip off a corner to pipe the melted chocolate.
Instead of using melted chocolate for the mummy eyes and spiders, you can use food decorating gel or purchased decorator icing.
Use regular pretzel twists or mini pretzel rods for smaller versions of these Halloween dipped pretzels.