Prepare cake mixes and bake according to directions.Prepare pudding mix and chill until ready to assemble. Crumble white sandwich cookies in small batches in blender, they tend to stick, so scrape often. Set aside all but about 1/4 cup. To the 1/4 cup cookie crumbs, add a few drops green food coloring and mix using a fork. When cakes are cooled to room temperature, crumble into a large bowl. Toss with half the remaining cookie crumbs and the chilled pudding. gently combine. Line new, clean kitty litter box. Put mixture into litter box. Put three unwrapper Toostie rolls in a microwave safe dish and heat until soft and pliable. Shape ends so they are no longer blunt, curving slightly. repeat with 3 more Tootsie rolls and bury in mixutre. Sprinkle the other half of cookie crumbs over top. Scatter the green cookie crumbs lightly over the top, this is supposed to look like the chlorophyll in kitty litter. Heat remaining Tootsie Rolls, 3 at a time in the microwave until almost melted. Scrape them on top of the cake and sprinkle with cookie crumbs. Serve with a new pooper scooper.