Preheat oven to 375 degrees. Line a baking sheet with parchment paper and set aside.
In a small bowl, mix together BBQ sauce and sriracha. Toss hotdogs in the sauce
Unroll the crescent dough and seal the seams of the triangles to create rectangles. Using a pizza cutter, cut strips (about 1/4" thick) of dough. Stretch the strips to make them longer and wrap aroud the hotdogs, leaving a small opening for mummy mustard eyes. Place on baking sheet and repeat this process until all hotdogs are wrapped.
Whisk the egg and gently brush the wrapped mummies with the egg wash.
Bake the mummies for about 12-15 minutes, until crescent dough becomes golden brown. Remove from the oven and let cool.
Using a toothpick, dot mustard on each mummy to create eyes.
Serve on a platter with extra Ketchup, mustard, and bbq sauce for dipping!