Fill the celery with peanut butter. For best results use a piping bag or a freezer bag with one corner removed. Make the head end of the snail by overfilling the celery slightly. Let the peanut butter trail off a little at the end of the celery to create a tail.
Blot the side of the apple slice with a paper towel to make sure it is dry. Make arcs on the apple slice with caramel sauce. Insert the apple into the peanut butter.
Poke the broken curves of a mini pretzel into the head end of the peanut butter for the antennae. Make eyes with mini chocolate chips.
Chill until ready to serve.