Heat oven to 350°F (325°F for dark or nonstick pans). Place paper baking cup in each of 24 regular-size muffin cups.
In large bowl, beat cupcake ingredients with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Divide batter evenly among muffin cups.
Bake 18 to 23 minutes or until tops spring back when lightly touched. Cool in pans 10 minutes; carefully remove from pans to cooling rack. Cool completely, about 30 minutes.
Stir paste food color into frosting in container. Spread frosting over cupcakes.
To decorate cupcakes, poke 1 pretzel piece into each cupcake for stem. Cut each gumdrop leaf into 3 slices. Poke 2 gumdrop leaves into top of each cupcake on either side of pretzel stem. Poke half of gummy worm into each cupcake. Store loosely covered.