It doesn't really very, but here is what you need.Edible: Rice Krispie Treat = Rice Krispies Butter Marshamllows Marshmallow Fondant (MMF) = Marshmallows Water Powdered Sugar (optional jell-o for color and flavoring) Corn Syrup for "glue"Food coloring (What I used: black for cats and decorations for skulls, ghosts, and pumpkins; orange for pumpkins; green for pumpkin decorations) (You can use liquid or gel coloring.  If you use liquid, I usually use that as a substitute for some of my water when I melt the marshmallows.) Crisco or Non Stick Spray (I use the spray) - to put on your hands while working with the rice krispie mix.  It helps stop the marshmellowy mess from completely covering your hands.Inedible: Pot for making Rice Krispie MixBowl for Rice Krispie Mix (if you leave it in the metal pot it will stick like crazy, I use nonstick spray on a glass or plastic bowl and transfer the mix while I'm shaping my treats)Silpat Mat or Similar Alternative (like usual, these are AWESOME when working with MMF)Halloween Cookie Cutters (I got these because there was a variety of shapes in one package and they were smaller than what I usually use; it seems like all my holiday rice krispie treats have been getting too big, these are perfect for personal sized snacks.)Pizza Cutter - everyone has one of these, but it is really nice to have for cutting strips with fondantPiping tips or something similar you can use to cut out small circles - I've used these for various decorating projects and they are just nice to have :)

Pick out your shapes!  I decided I had to do a pumpkin.  I also wanted to try the ghost, skull and the cat while I was at it.  After doing this I would strongly suggest, if you are using small cookie cutters like me, to not do ones with little bits on it.  For example: it was hard to fill in the little ghost tail.  Not impossible, just hard.  I would still do the ones I did, but doing the little kitty ears, and making sure you could tell what they actually were, was hard.Steps: Move rice krispie mix to another bowl.  I sprayed a glass mixing bowl with non stick spray and poured mine in there.  I say to move the mix, because the first time I did this I left it in the pot I made it in and by the time I got to the bottom it would not come off the pot.  Real pain that was.Spray your cookie cutters with non stick spray.  I did this a little late and I think that was why the mix would stick.  Also, plastic might work better here than metal cookie cutters.Smash the krispie mix into the cookie cutters.  And when I say smash, I mean smash.  You want to hear the krispie crunch as you smush them in.  This gives them a nice strong and defined shape.Set them aside to harden up a bit before moving on.

when you dropped the box of rice krispies. :( I know, sad day, sweep it up and you'll be fine. It is hard to hold that big box with one hand while measuring out 6 cups of rice krispies.

I don't really like this method, but it is an option. Take out your pizza cutter and cut out strips of your MMF that is roughly the thickness of the rice krispie treat shape. Then use the cookie cutter that matches your shape (in this instance, pumpkin) and cut it out in MMF. Wrap the strip around the side of the treat.  If there is extra, fold it over the top as show in the pictures.Stick the cut out fondant right on top.  This does the trick, but doesn't look nice in my opinion.

This is the method I usually use that gives the best results.  It is very time consuming though. Roll out your MMF.Lay it over the top of the rice krispie treat you want to cover.If the fondant is soft it will mold nicely to the treat.  Just ease the the fondant over the edges until you have covered the top and sides of the treat.Cut around the bottom edge. If you have extra hanging down, just smooth it over the bottom of the treat.Repeat for all the treats! There is another very easy way to do it.  Simply cut out the same of the treat in the fondant and just put that on the top.  It doesn't look as complete, but you still get a tasty treat.  If you just cut out the treat in fondant like this, you can cut it out thicker than you would have if you had covered the whole thing.

Time to decorate them!  Us a decorating paint brush to brush on corn syrup to use as clue for all your little pieces.Pumpkin (2 options) Traditional Pumpkin: Roll out some green and cut out a couple small circles of green using a decorating tip.Smush the circles a bit to give them more of an oval or diamond shape.Arrange the rolled out piece as a vine and put your little oval leaves on the vine.Jack O' Lantern: Cut out a couple circles for leaves. (you don't have to, but they look cute)Cut out larger circles from the black using a larger decorating tip.Smush the larger circles to look like triangles and arrange them as eyes and a nose.You can get more complex and creative!  Go crazy!  I would love to see what people do!SkullCut out 2 larger circles and a few smaller ones using the decorating tips.Put the big circles on as eyes.Put on the smaller circles as teeth and kind of smush them up against each other to make them more oval.GhostCut out three small circles using the tips.Arrange them as eyes and a mouth.

Eat up!  You can see I just cut out shapes for all those colored ones.  It is a nice easy way to do it if you don't have time to completely decorate them all. Hope you enjoy!