Place raisins, almond or peanut butter, honey and cocoa powder in a food processor and process until a thick paste forms.
Transfer to a large bowl and stir in cereal, using your hands to mix in completely. Press mixture into 12 balls, then press lightly onto a foil or wax paper-lined baking sheet.
Spread a small amount of melted chocolate on the bottom of each and slide 4 small sticks of pretzels under each to form the spider legs.
Dot the head with a small bit of chocolate fudge and stick the eyes on.
Refrigerate until firm.