Begin construction by cutting a half-inch strip of corrugated cardboard, peeling away the top paper liner to expose the wavy internal fluting, and trimming the strip into a jagged saw-tooth ridge. Paint two cardboard toilet paper rolls and the jagged cardboard ridge in mottled shades of dark olive-green and deep forest green. Join the two green tubes side-by-side using heavy-duty craft glue. Glue the jagged cardboard ridge vertically down the center seam between the two tubes to form a raised reptile spine. Cut a strip of small triangular teeth from white craft foam, gluing the teeth along the front bottom edge of both barrels. Glue two large dome-shaped green or yellow plastic googly eyes to the upper front of each tube so they peek above the barrel profile like an alligator skimming the water. Attach a durable dark green nylon webbing lanyard through punched side eyelets.