Our Hippopotamus puppet was designed to especially feature the big mouth opening up wide, full of big teeth. The big mouth was very important, because we were advertising the debut of Coors Wide Mouth cans, with extra big openings. We approached creating the hippopotamus puppet by sculpting the full head and body in water based clay, then molding it in fiberglass, creating a core, the casting the skin in silicone rubber (chosen for its toughness and durability operating in water), and mounting the skin on a cable operated mechanical fiberglass core. The teeth and pallate, eyes, and ears were created and put in separately.

Our hippo puppet was made to match the size of a pygmy hippo that was also used in the Coors spot for the one shot where the hippo walks into the room. Pygmy hippos have different heads and smaller mouths than regular hippos, so the pygmy hippo could not be used for all of the shots. A quick cut from the walking pygmy hippo shot then featured our hippo opening up its mouth in full glory, and the substitution is not even noticed.

In the opening shots of the spot, our hippo is featured coming to the surface in a pond and opening up its big mouth. To achieve this surfacing hippo effect, we filled tanks in the body of the hippo with air, strapped the hippo to a weighted base plate on the lake floor with quick release mechanisms, and the hippo rose up and emerged up through the surface of the lake beautifully and perfectly every time.