In advance: Mold candy pumpkins. Set pumpkin cutter on non-stick cookie pan. Fill 1/4 in. deep with melted orange candy. Chill until firm.
Also: Make round bases. Prepare cereal treats mixture. Press into lightly greased sheet cake pan, 1 1/2 in. deep; let cool. Cut rounds using metal cutter. Cover with melted candy; tap to settle, chill until set.
Make fondant grass. Tint fondant and roll out 1/8 in. thick. Cut 10 x 1 1/2 in. strips. Make V-shaped cuts into top edge. Attach around base with melted candy. Shape edges for natural look.
Decorate pumpkins with melted candy in cut parchment bags. Attach to base with melted candy.
*Combine Leaf Green with Lemon Yellow for green fondant shown.