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.
Repeat process with mini cupcakes, mini cookies and mini M&M's.