preheat oven to 400 degrees. mix the cream cheese, jack cheese, onion and salt until blended well.
roll out the crescent dough, but do not separate them into triangles. keep them as rectangles and close up the perforations by pinching the dough together, or by pressing it with your finger.
using a pizza cutter, slice each dough rectangle into about 10 thin strips.
fill each jalapeño with the cheese mixture.
wrap each filled pepper with strips of dough, leaving and open space near the top for the eyes.
bake for 8-10 minutes, until golden. place eyes on mummies as they cool.