Preheat & Prep: Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper. Unroll the crescent dough and separate into triangles. Using a pizza cutter or knife, cut each triangle lengthwise into thin strips (about 4-5 strips per triangle).
Wrap the Mummies: Take one hot dog. If using cheese, wrap a thin strip of cheese around it first. Then, take 2-3 dough strips and wrap them around the hot dog, stretching slightly, leaving a small gap near one end for the face. Crisscross the strips randomly like bandages. Place on the prepared baking sheet. Repeat with remaining hot dogs.
Bake: Bake for 12-15 minutes, or until the dough is golden brown and puffed up.
Add Eyes: Let the mummy dogs cool for a minute or two. Dip the end of a toothpick into mustard or ketchup and dot two small eyes onto the face area. Alternatively, stick on edible candy eyes using a tiny dab of mustard/ketchup as 'glue'.
Serve: Serve warm with ketchup and mustard for dipping.