Pipe zigzag of white icing onto cookie. Smooth with spatula.
Decorate butterfly. Use round decorating tip to pipe an elongated stripe of green for the body. Pipe 4 elongated wings in a different color. Pipe a large dot to create the head. Add candy eyeballs. Add coupler and fit with tip 2 to ad fine detailing like smile and lines of contrasting color on top of wings.
Decorate caterpillar. With the round tip, pipe a large dot to create the head. Alternate icing colors and create 4 more dots to form the body. Add candy eyeballs. Add coupler to decorating pouch and fit with tip 2 pipe the smile.
Decorate worm. Using the round tip to pipe a large dot for the head. Pipe an "S" shaped tail using round tip. Add coupler and fit with tip 2 to add fine detailing like smile and tail design.
Decorate snail. Use the star tip to pipe a spiral, starting at the center of the cookie and working outwards. Use a round tip to pipe a large dot forming the head. Add candy eyeballs. Add coupler and fit with tip 2 to decorate with fine detailing like smile and antennae.