1. Spread all cupcakes with frosting. Separate Double Stuf Oreo cookies by carefully slicing down, leaving filling on one side of each sandwich. Scrape any cookie crumbs off filling. Place 2 cookie halves, filling side up, on each frosted standard-size cupcake. Gently press brown M&M's into Oreos to finish eyes and an orange M&M's into frosting as beak. Cut pointed ears out of leftover cookie halves and tuck into top of each cupcake behind eyes.
2. Repeat process with mini cupcakes, mini cookies and mini M&M's.