01 - In a large mixing bowl, combine 2 boxes of lime-flavored gelatin with 2 cups boiling water. Stir thoroughly until the gelatin is fully dissolved, then add 2 cups cold water and mix to ensure an even consistency.
02 - Divide the gelatin mixture evenly among 8 clear cups, filling each about halfway. Place the cups in the refrigerator and chill for 1 hour until the layer sets.
03 - In a separate bowl, whisk together 1 cup sweetened condensed milk and 1/2 cup hot water. Add 1 box lime-flavored gelatin and mix until the gelatin is completely dissolved. For a vivid color, mix in a few drops of green food coloring if desired.
04 - Allow the slime mixture to cool to room temperature, ensuring it does not begin to set.
05 - Once the jello base is firm, gently pour or spoon the cooled slime mixture over the set jello in each cup, filling to the top. Return to the refrigerator and chill for at least 1 hour or until fully set.
06 - Before serving, decorate each cup with candy eyeballs or gummy worms for a festive finish.