Fish 'N Flush

http://www.fishnflush.com/about.html

“Fish ‘n Flush is a patented, two-piece aquarium toilet tank, designed by AquaOne Technologies, Inc., an innovator of water-management systems. Fish ‘n Flush fits most two-piece toilets and turns the bathroom into the center of attention with its unique design of an aquarium that wraps itself around a clear inner tank."