When made of Jell-O®, this creature isn't such a frightful fellow. He is, however, a wee bit jiggly -- and sure to make your children giggly. (Party tip: Prepare steps 1 through 3 ahead of time and let the guests do steps 4 and 5 at the party before they eat the monsters.)
Paint scars and mouths on a ceramic plate as shown (squiggly mouths and "stitches" are covering a plate). Let them air-dry over night.
Prepare the gelatin according to the package directions. Pour slightly cooled gelatin into the cup, stopping 1/2 inch from the top.
Refrigerate until the gelatin is partially gelled, then remove the cup from the refrigerator and use a table knife or spoon handle to push 2 cherry eyes into the gelatin. Refrigerate again until the gelatin is completely set.
Use double-sided tape to attach the neck bolts. Peel the scars and mouths off the plate and place them on the cup (they'll adhere like Colorforms). If it's difficult to peel the shapes off the plate, stick the plate in the refrigerator for at least 10 minutes, and they should come off easily. Variation: it may not look as cool as the paint, but kids can also use a permanent marker to draw the face on.
Cover the top of the gelatin with crushed Oreos® hair. Don't wait too long to gobble up the monsters, or the hair will get soggy.