Insects have a high food conversion rate, e.g. crickets need six times less feed than cattle, four times less than sheep, and twice less than pigs and broiler chickens to produce the same amount of protein

Bug Sushi

One of the Puffer fish’s (Tetraodontidae) defense mechanisms is the ability to fill its extremely elastic stomach with water (or air when outside the water) making it much larger and nearly spherical in shape. 

The Tetraodon MBU puffer is the largest freshwater species of puffer fish. Getting 22+ inches in a home aquarium.