Fun World Heart Jello Mold Halloween Decoration - Make Your Own Gelatin Hearts - Terrify Your Friends, Kids and Halloween Party Guests Fun World heart jello mold halloween party decoration. Make your own gelatin hearts. Shock and terrify both your halloween friends and your normal friends with jello hearts. This jello mold will freak kids out, too. Use delicious gelatin and make tasty heart treats. Realistic looking, measures 6x6.25x2 inches. For even more icky fun, use with our brain and hand gelatin molds.