exacto knife or carpet knife
Styrofoam "cooler" for big rocks
2' x 4' piece of StyrofoamB. insulation board
Pieces of scrap foam board, purchased or found in packing material
Styrofoam packing "peanuts"
Low-temperature glue gun and glue sticks
One package plaster cloth
1" paintbrush
Scissors
Hobby saw or small hand saw
Shoe-box-size or larger container that will hold water
Water
Paints (non toxic)
* Light earth-toned
* Dirt-colored
Black marker

1. Use scraps of insulation board to build around the bottom of the cooler or make small "rocks". The scraps can be any size or shape, as long as they fit the space designated for your rock. Using a low-temperature glue gun, glue the pieces of insulation in place to begin building the rock. Stagger the pieces to create a realistic, rugged-looking shape. Use a hobby saw to cut blocks of insulation foam to fit the space allotted to the rock. The rock shouldn't be taller than your enclosure's walls. Continue to glue and build up the front of the mountain until the bottom half of the rock is complete.
2. Repeat with the lid making sure they still fit together, but the lid can come off.
3. Put the top on the rock. Now build up the top of the rock by gluing scraps of Styrofoam insulation as desired. Use pieces of various sizes to create contours, and use a hobby saw to cut contours into the mountain. Glue on packing peanuts to create bumps and foot holds. Complete the rock as desired. Make sure cooler isn't glued shut.
4. Fill the shoebox-size container half full of water. Using scissors, cut a piece of plaster cloth about 4" long. Let it soak in the water for about 5 seconds. Drag the cloth strip along the side of the container to eliminate excess water. Place the wet plaster cloth over the Styrofoam sides of the rock, molding the cloth to the rock with your fingers. Dip a 1" paintbrush into the water, and brush the wet plaster cloth to eliminate bumps and air bubbles. Repeat the process until the entire mountain is covered. Let the mountain dry overnight.
5. Using carpet or exact knife divide the top and bottom making sure the top is still a "lid". Replace top.
6. Finish the rock by spray-painting it with earth-toned paints. If the room is not well ventilated, wear a mask. Use a light earth tone for the base, applying the paint in light, sweeping motions. Use a darker color to create and color darker patches of rock.