Grind frankfurters (hot dogs) in a food chopper or food processor. Mash baked beans with a fork. Add pickle relish and mustard. Combine with ground hot dogs and mix well.
Make biscuits according to the directions on the mix box. Roll 1/3 of the dough to 1/8 inch thickness. Cut rectangles about 3"x5" and shape a heaping tablespoon of meat filling down the center of each. Form into rolls and pinch ends of each Hallo-Weenie together.
For masks, roll out another 1/3 of the dough, and cut circles, about the size of a coffee can. Place filling on half of each one, use a small round cutter to cut the eyes. Fold this half over the filling and pinch to seal.
To make Jack-O-Lantern faces, cut dough into rounds with a cookie cutter. With a sharp knife, cut eyes and a mouth from half of the rounds. Put filling on the plain rounds, cover with the cut-out rounds and seal edges. (Tip: You don't need to cut out a space for the mouth, just slit the dough in a smile or frown, and it will stretch open when you place it over the filling.)
Arrange the Hallo-Weenies on a greased baking sheet and bake at 425 degrees for 10-12 minutes.