Low temperature hot glue gun or other craft glue of your choice
Place the green Jello with the lid facing down, and use glue to attach two googly eyes to the front of the container. Leave a small amount of room above the eyes to allow space for the eyebrows to be drawn on.
Draw a Grinch face onto the front of the green Jello around the googly eyes. You can see the photo for reference.
Using glue, attach a red pom pom to the top of the Jello snack to serve as the base of the Santa hat.
Glue a smaller sparkly white pom pom to the top of the red pom pom, make it slightly off to the side to give the impression of a hanging hat.
Attach a few layers of thicker white yarn around the bottom of the red pom pom with glue to create a brim for the Santa hat.