1 (18.25 ounce) box German chocolate or spice cake mix
1 (18.25 ounce) box white cake mix
1 (1 pound 4 ounce) package vanilla sandwich cookies
1 large box vanilla instant pudding
Green food coloring
12 small Tootsie Rolls
1 NEW Kitty Litter Box
1 NEW Kitty Litter Box Liner
1 NEW Pooper Scooper

Prepare cake mixes per package directions. Bake them in any shape pan you'd like, you'll be breaking them up later on, so it doesn't matter what they look like. Prepare pudding mix per package directions. Refrigerate until well chilled. You may or may not need the entire package (save the leftovers to eat later on.)

Put the cookies into your food processor (with the filling). Pulse until the cookies are crushed. Don't overdo it, as it is supposed to look like kitty litter. Scrape the sides of the processor bowl often as the crumbs tend to stick. You'll need to do this in small batches.

Add a few drops of green food coloring to one cup of the cookie crumbs. (This is the chlorophyll in the kitty litter.)  You can put the crumbs into a jar, add the food coloring and shake until it's fairly well mixed.

When the cakes are cooled to room temperature, crumble them into a large bowl. Toss with half of the remaining (uncolored) cookie crumbs and enough of the pudding to make the mixture moist, but not soggy.

Line the kitty litter box with the new liner; add the cake/pudding mixture and spread it out. Unwrap three of the Tootsie Rolls and heat them in the microwave until they are soft and pliable;  don't melt them!  Shape blunt ends into slightly curved points (use your imagination).  Repeat with three more Tootsie Rolls.  Bury the shaped Tootsie Rolls in the cake mixture, allowing some of them to stick out of the top at random intervals. (Again, use your imagination.)

Sprinkle the remaining white cookie crumbs over the mixture, then scatter the green crumbs lightly over the top.  Heat the remaining six Tootsie Rolls, three at a time, in the microwave until almost melted.  Scrape them over the top of the cake and sprinkle with crumbs from the box.