Melt the candy melts and spread them onto the insides of a dome-shaped mold. Place in the freezer until fully set, about 10-15 minutes.
Tie a knot at the end of strings and place them in small silicone molds. Pour some chocolate into the molds and place in the freezer. These will be used as the strings to hang the pinatas and the chocolate base keep them inside the pinatas.
Unmold the domes onto a sheet of parchment paper and draw any facial features with more candy melts. For ears and arms, draw them onto the parchment paper first, them place the domes on top. As the chocolate hardens, it'll attach to the domes. The candy melts will set at room temperature, but you can transfer the decorated domes to the freezer if you'd like them to set quicker.
Fill one half with gummies and a string, with the chocolate base inside the half. Spread some chocolate around the edge of the dome and place the other side of the dome on top. Place in the freezer for the chocolate to set.
Tie the other ends of the strings onto a hanger or a pole, then smash to reveal the candy inside!